motobecane catalogue specs of different models ...

c.1974: https://www.flickr.com/photos/strongl...n/photostream/
c.1975: https://www.flickr.com/photos/strongl...n/photostream/
c.1976: https://www.flickr.com/photos/strongl...n/photostream/

from these, it appears the GJ model frame came in both red (w/blk) or silver. the GR frame came in both black (w/red) or silver. but i still don't know the exact date of my own GR. oh well...

I think the frame looks exactly like my '75 Grand Jubile. Mine also did not have a tubing label. Not a bad bike, but I gotta say my Mirage Sport seems better than it in every way though, lighter, shifts better, and rides more comfortably. I'm guessing the cheap wheels and tires might be to blame for that, mine weighs in at 27 Lbs rather than the advertised 24.

Wheels and tires can turn a POC into a gem - and vice versa.
Three extra pounds makes me wonder if you have steel wheels!

Nope, they are aluminum, but being light sure doesn't look like it was factored into the design of them. I don't have a rear wheel that would drop right in either to see what it would be like. I don't suppose dropping in a 126mm wheel into a frame that is respaced to 135mm would hurt anything?