Classic & Vintage - Unknown MAFAC brake calipers?

If found these in a box of goodies I picked up some time ago. I've probably had them for a few years now but finally dug through the whole box of parts. I found these, two Stronglight 93 cranksets, several French bottom brackets, a Stronglight headset, and two sets of Mafac 'Racer' brakes and levers. Not to mention a pile of old Simplex derailleurs both new and used. Most of the parts were early 70's at best, some maybe even older. It took also took me a while to figure out what some of the fuzz was in the box, but it turned up to be a disintegrated set of old sew up tires with the tubes removed. The threads are so rotted the tires fell part to the point they resembled corn silk in a box.

Anyhow, these are different from any I've seen before, the shoe clamps are larger than those on the Racer variety, and the straddle wire is double ended. They are marked only 'MAFAC' with no other engraving.

http://img194.imageshack.us/img194/4500/mafac1.jpg
http://img64.imageshack.us/img64/7786/mafac2.jpg

They look to me to be one of the many styles of Racer models.

I didn't realize they made 'Racer' calipers without 'Racer' scripted on them?
Racer parts don't fit, the bolts are different, the straddle cable is it's own, and the pad clamps are different.
The reach is about the same.

Any idea what years?

Thats so weird. Thats the same model that I bought at the Chicago Swap yesterday. I have no idea what year its from. Mine came with black plastic bodied drilled levers. What you do when the cable goes, I dont know. Mine polished up really nice, and I thought the pad adjustment was easier with that camlike thingy.

The Racer model that is most common was THE brake on just about all french bike boom bikes. I would think this model is a bit later, maybe mid to late 70's. There seemed to be several lesser versions of the Racer as the 70's wore on.

Whats odd is the casting on these brakes look nicer than the Racer. Some versions of the Racer especially later ones the castings got sort of rough. Either that or they applied some sort of anodized finish that looked rough. The camlike fitting in my opinion is easier to adjust and looks mechanically superior to the typical Racer pad adjuster. All that leads me to think its earlier than the Boom era. Very confusing.

I didn't realize they made 'Racer' calipers without 'Racer' scripted on them?
Racer parts don't fit, the bolts are different, the straddle cable is it's own, and the pad clamps are different.
The reach is about the same.

Any idea what years?

Late versions of the Racer were only marked "Mafac," without the "Racer" name. Early versions were marked "Dural Forge."

It looks like they use the same nearly unobtainable bridge wires as the late Competitions used. Hilary Stone was selling those wires for $14 plus shipping from Bristol England.

Those look thinner or more streamlined then the Racer models. I can't say what they are but I know I've never run across a set before. I'd bet on them being a step or two above the Racer or just older. The brake shoe clamp barrels or mounts or what ever you call them look way bigger and heavier duty than on the Racer, which would go against normal advances to save weight as the years progressed. I have a few older Mafac catalogs and their not in any of them, I believe I have one from the early/mid 70's and another from the early 80's. The double ended straddle cable tells me newer though.

The picture below shows 3 versions of "Racers" with identical measurements.
187181
The brake to the right - to my knowledge one of the last versions - is what I thought at first glance to be the same as the ones shown by oldlugs (which I think are "Racers" as well). Except from the black washers/bushings instead of the common red ones and the bigger brakeshoe mounts.
Both details I have not seen on "Racers" so far.

The thing that caught my eye was the pads. They are very different than any of the three shown in the photo above. They don't have th eshank that passes thru the clamp.

The brake shoe shanks are thicker than those on the Racer, and the caliper as a whole is better finished. The arms are thicker, not by much but enough you can tell by feel, and the black washers are some sort of fiber not plastic bushings. The shanks of the pads also don't tighten down the same way, the barrels are hollow, the rear stud has a hole in it that pulls tight around the brake shoe shank. It eliminates the washer that would normally protect the aluminum slot. The slot is the same width and I suppose I could use Racer brake shoes and hardware. The bolt and other bushings closely resemble the old Competition models.
Something that keeps bugging me is that every other part in this lot was older, pre '70 or older, unless the box was what was stripped off one or two bikes that had been upgraded before hand?
I guess I'll never know for sure.

I think they are more Competition like than Racer like... the straddle wire is like the late Competitions, note that the oversized chrome barrel arrangement that the brake block stud inserts into, not like I have seen before. I like them. But I do like the quick release feature on the earlier Competitions.... I do have a set of Mafac levers with brake quick releases as part of the design.... Now those are rare too.

The second image finally would open, note the fully closed block shoe... These must be post CPSC influence.

Those shoes may not be original? I was thinking that maybe they were Racers with brake barrels and shoes from another brake? The black washers do look older to me.

... box of parts. I found these, two Stronglight 93 cranksets, ... two sets of Mafac 'Racer' brakes... Most of the parts were early 70's at best, some maybe even older...

The Stronglight 93 crank was introduced in late 1967 or 1968. For me this would indicate a first approximation of the earliest vintage of the box' contents if it was taken from one or two bikes.

Sometimes you find a date code stamped into the rear side of the front lever-arm of the "Racer" brakes (e.g. "10 76" or "03 77"), often hardly visible because covered by grime. Did you check for this?
At least you would know the year of production.

The only markings are 'MAFAC' on the front, and 'Made in France' on the back. I've seen some Racer models with date codes, but there are none on these.

Hmm... where was that handy page with all the MAFAC stuff on it again, can't seem to find it now... It was a great help to me when I needed to identify my gold anodized competitions :)

Here's the 1979 MAFAC poster. I don't think it's any help, though.

http://www.velo-pages.com/main.php?g2_itemId=2108&g2_imageViewsIndex=1

The one thing that the poster there does show is that these are similar to the Competition model in parts, they do not use a top hat shaped bushing like the red one on the Racer models. It looks like the competition but with a different straddle cable end shape.

Something else I forgot to list that was in this box was an older TA crank, according to the velobase site, it's an early 70's Professional model crankset.
Any idea what this may have come from?
I'm sort of trying to figure out what kind of bike all this came from.
The Stronglight 93 cranks could be Peugeot, but I don't recall seeing these on anything in particular back in the day.