I think you might be referring to dropout adjustment screws. They typically go in at the back of the rear dropouts and locate/limit your rea hub's axle position in the dropout slot. I suspect that Campagnolo's version of those adjusetment screws would work with those dropouts. They are readily available from sellers at eBay, they come with either a knurled brass barrel shaped knob at the end (just like in the pic you posted) or a later black plastic ear shape knob. The the ones with the ear shaped knob makes it easier to turn or adjust, but older early 80's and 70's bikes came with the knurled barrel shaped knobs. You need to make sure that you get the right legnth as they come in long and short versions to match whatever legnth slot you have on your dropouts. You will have to shop around a bit as they are sold at wildly varying prices at eBay
Chombi