You should get in the habit of photographing bicycles from the other side - we can tell oh so much more from that angle. It looks to me like the cranks, at least, are Campy...maybe the shifters, too? The parts may be very valuable, if they date from the '50's. The frame itself has value as well, Mac Leans have a following among people who know. I really can't see enough detail to give you a guess - but that is a Pista stem on the handlebars, and depending on brand, may be worth up to a hundred dollars all by itself.

Can you give us some additional photos?