Thanks for all the advice!
Panthers007: I have no plan to slaughter cats or frames!
Sixty_Fiver: It's a late '60s Bertin bike that was rusting away at some guy who hoped he would get to retore it. I've picked it apart and am now trying to restore the various parts, starting with the frame. I hope to be able to use as much as possible, but I'm unsure how good I can make the brakes, the saddle has an ugly hole, the pedals are quite rusted and I would want to ride pre-built wheels before I make any effort in building a wheel myself. Sorry for the stupid question: Is this bike no doubt equipped with 3/32" ( I guess so since it has five gears on the back wheel)? Is there a way for me to measure this?
bikingbrit: Thanks for that tip!