My conversion worked ok with brakes. The diacompe 610 that was on the front (bike was missing the rear when I got it) was able to reach a 700 in the rear. I had to buy a diacompe 750 for the front though because the 610 just barely didn't reach.

$3 in the used shop parts bin. Spent some time polishing it and it looks brand new (and even better, I painted the space the logo sticker used to be with the frame color paint).