why don't you go to MASSART or EP LEVINES or one of the other photo schools in boston ( AIB / SMFA / NESOP )
and ask someone there who may be familiar with roll backs+graflock backs to take a look at your camera &C ...
i am south of you about 1.5 hours, i'd be happy to meet with you
someplace random to take a look at your camera ( and bring my speed for comparison )
but i don't travel light these days ( i have 3 assistants i have to bring with me everywhere ) .. so it might be tricky ...
Haha, I GO to MassArt
Problem is, I'm the one people usually come to when they're scratching they heads over cameras
Oh and the entire photo lab is torn apart right now for renovations. More digital labs
But yea shoot me a message if you'll be in Boston.