With my experience, I can't see running a 102mm Campy BB on a new Steamroller. I recently picked up an '05 Steamroller frame and built it up with an old Suntour Superbe road crank (pre-Superbe Pro) that supposedly mirrors non-Chorus/Record Campy in terms of BB fit (ISO taper). I originally ran it with a Campy ACH 111mm bottom bracket, but my chainline was off quite a bit.

I picked up a Miche Primato 107mm bottom bracket to remedy the chainline, but now the clearance between the inside of my crankarm and chainstay is pretty tight. I had to file off the tabs that hold the inner chainring in place (effectively making it a track crankset) just to clear the 'stays, and even then I've only got a few mm's clearance. The BB isn't mounted symmetrically in the frame, either: I've got the non-drive side cup screwed into the BB shell a few mm's and the drive side cup sticks out from the shell a few mm's. When both were flush to the BB shell, the chainring bolt nuts scraped the chainstay.

FYI, I'm running a 45t chainring on the outside of this crank, and the length is 170mm. I've got fairly good chainline now with a Suzue Basic hub and Dura Ace cog. When it comes time for a wheel upgrade, the slightly wider chainline of a Surly hub should get me dead-on.

I can take and post pictures of my setup if that'd be helpful. Good luck.