Well Automag......I've never seen or heard of a Winchester Model 94 without a serial number......but I'm not an expert on Winnies, so I'm going to refer you to a real Winchester expert, on another website.....
Go to: http://forums.*********.com/forum.asp?FORUM_ID=2
......and ask for "Bert H." He really knows his stuff on Winchesters.
Good luck and let us know what you find out.