If you can be bothered scanning them, Mark Bulgier at bulgier.net is usually happy to put them up on his catalogs page: http://bulgier.net/pics/bike/Catalogs/ (it isn't working at the moment.) At least, he's put up catalog scans that I've sent him in the past. Check what he has before you start scanning though, there are a fair few there.

Velobase also has a scanned catalogs page, but you would have to sign up to contribute: http://velobase.com/Resource_Tools/CatalogScans.aspx