Some of the non-painted parts on the front are engraved with the number 6164 or just the number 64. The only identifying marks cast into the frame are on the little bracket that holds up the thread spool tray. The number 600 is cast into it. The name "Champion" is painted on one side, as well as some letters that I think might say "PATENTED" underneath it. On the same side, up near the top, is the admonition "Do not put oil in the wax".
The manuals I have found so far are for:
Champion 30 & Pearless (narrow throat)
Champion 50 & 52" stitchers
Champion 77 McKay
Champion Harness Stitcher (wide throat)
The machine is about 26" tall.