Kevin, A fellow just brought a circa '78-'79 Colnago Super into my shop with the same brake set up. Same stamp on the driveside dropout and the fork steerer tube. I used to own an Viner from the same era that had the same thing going on. Late 70's-early 80's seems to be a bit of a "transitional" era...Just as brake mounting was changing, so too was the over vs. under BB cable routing. And both bikes had short 1010 dropouts with the porta catena mounting holes.
> Date: Thu, 15 Jul 2010 07:10:52 -0700
> From: firstname.lastname@example.org
> To: email@example.com
> Subject: [CR] 1978 De Rosa - mismatched brake centerbolt mounts
> Congratulations to the very astute Ray Dobbins for being the first person to
> point out the anomaly on my 1978 De Rosa photos posted to Wool Jersey yesterday:
> Note the use of a nutted front centerbolt and a recessed rear. Fork is
> definitely original to the bike, and suspect it was simply a shop error,
> grabbing a prebuilt nutted brake fork from the rack and fitting to a recessed
> rear frame. Greg Softley's ex-1975 De Rosa has a similar mismatch (think he
> purchased this from Ken Denny), although opposite of mine (recessed front &
> nutted rear):
> Would be interested if anyone else owns a bike from this period with similar
> mismatched brake mounts.
> Kevin Kruger - Grantville, PA USA