Managed to lose my pinch bolts and having bought some replacements it seems that modern ones are slightly too big.
Have rung round a few local bike shops and turned up nothing. Am running 700c wheels on an old 27" wheel frame so need a long reach.
My current brakes are these i think :
http://static.lfgss.com/attachments/15735d1254315346-weinmann-brakes.jpg
I'm thinking of just buying new ones from ebay such as item number 261109629676. Will the new brakes be any better? I could justify wasting money on them then :-P If they'll be the same/worse I'll just keep hunting for pinch bolts I guess.