We all know that many ex FCC staff formed IF. This looks like a Somerville made Yo in all but name, due to cable routing, canti bridge design etc. Its 1in headset with no serial would give me the impression it was originally an early IF staff bike 95ish onwards. FCC staff were known to leave serial numbers off, weld symbolic logos on and stamp unusual serial codes on BBs that did not follow FCC normal factory serial sequence. It should ride really nice with 853 tubing and Yo geometry.
You may have more luck hitting up ex IF staffers on FB or even Fatcogs. There are a few and they are usually pleased to help.
MP
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Lover of FATs & single pass welds.
Someone once said “we spend the rest of our lives searching for what we once had”
If you can’t explain something to a six year old, you don’t understand it yourself. Einstein's rule.