Look on velobase.com to see what type of calipers you have. As JohnDThompson said, late Super Record calipers have script logos, as do the Gran Sport, Victory ones (both have conical nuts, but of different types). None of them are bad brakes. As for rust, you can take care of that easily using an oxalic acid bath (but only for chromed or bare steel -- keep aluminum or zinc-plated stuff away from acid). Of course, where rust has formed, it will again, more easily than before it formed in the first place -- so you have to keep such parts oiled or waxed, and out of water.

It always helps to be an educated consumer; but just about everyone here has a "I wuz robbed" story or three.