I assume you'll switch it back to 700c then? There's the expense of new (old) wheels, or at least tires, rims and spokes if you keep the hubs. But you get better tire clearance, if you like fatties (and who doesnt?), plus the brake pads hitting the rim correctly: Priceless. I know, I'm spending your money, but this bike is historic and well worth returning to original if possible.

Finding a replacement Driver canti may be difficult. I've had a saved search for them on ebay for years, can't remember ever getting a hit. So if you like your brakes to match, maybe sell the one Driver, and with the money buy two Criteriums (normal Mafac canti), probably with enough money left over to pay a FB to reattach the missing canti boss.

I dunno, maybe I'm the only lunatic out there looking for Driver cantis. So hard to gauge "market price" for something that almost never sells. But I bet there's some dentist in Japan willing to pay a pretty yen for them.

BTW someone recently posted some photos of Jaques Anquetil using canti brakes in the TdF (presumably for their lighter weight), and in one of the pics you could tell they were Driver. I think, for the brief time on the market, they were the top of the line. Simlar to the 'Top 63' centerpull, that was only made briefly and now sells for megabucks.

Mark B