Ok, here's what I know. Not much. Fork is made by tange, and the stack height is correct, so may have been original to the frame, but meh...






Frame. Very light. Seatpost is 27.0. Vitus dropouts. Looks like prugnat S4 lugs. And,..... this certainly makes it a bit easier, (but I've searched for a couple of days). It says "custom crafted in cambridge for... (someone's name) " Only Mark's in the frame, besides the numbers 2 and 3 on the bb shell. I'm in the boston area, so I'm leaning toward cambridge massachusetts. Somewhere between 1975-1980. Due to the dropouts and suntour blue line derailleur that was on it. It may not have been original, but it looked it. I know chris chance was in cambridge, peter mooney in belmont.. but I dont believe he was building frames yet. Tom kellogg at merlin for a bit, but I believe that was later. Though the seat stays look a lot like his. I have a steel spectrum from 92.
Could also be england, .....
thanks for your time and good luck. Ivan

Well, if I lived in the Boston area, I'd take it over to Harris Cyclery (can I mention a business?) in West Newton. If Sheldon Brown was still with us, I'd bet he be able to help but perhaps one of the staff there might be able to provide some answers.

unusual tor those Vitus droputs to be on a frame with (appears) BSC/ISO BB threading, they were not used by many brands, which might support a custom-built frame. Tange fork could be after-market.tho it DOES look like it's also fro nutted brakes (correct?). Not a clue from me as to the builder!

Thanks, good idea on the Harris cyclery. Are they letting any one in the building yet? I'm in no rush.
here is a picture from the original listing. I asked the owner if he had any responses. He told me I was the only one. I'm sure the blackburn rack and mismatched parts threw some people off. Looks like the wheels and cranks off an early specialized. The grips on the bars are Morgan concepts.

I have a Mercier with those dropouts, late 70s/early 80s, French BB.

Nowhere near as nice as this frame.

Ok, if you thought I was giving up easily... never give up. I went by Harris cyclery earlier this week. As expected, no one is allowed inside. I parked in the back, and walked to the front. I could see people working on bikes, but a sign indicated I needed to call. Ok. I'll admit it was awkward making the call... "hi, I'm the guy at the front door..." I found myself at a loss for words... pretty funny looking back. I'm wondering if you've got anyone in there my age or older to perhaps help identify the builder. It took me a bit more struggling than that to explain myself. The guy I spoke to, john, told me he was intrigued and to meet him out back. We talked for about 10 minutes, and while he said beautiful frame a couple times, I'm no further along.
Here are a few more pics. Looks like it was built for 27" wheels, not 700c. Ok by me. I have a Hi-e wheelset I've been sitting on. Frame size is roughly 54 is seat tube, 56 top tube CTC.

Yes I knew it was for 27" before i spoke to john. I put those wheels on to see how it sat. Stance if you will.