Yes, great idea, T-Mar. But I'll only add to your data base if you promise to hang around past 10K posts.

OK. No pics but:

Circa 1973 Team Champion_____ 13104 stamped on the BB shell. No other numbers anywhere.

Circa 1975 Le Champion ________2904702 stamped on the non drive side dropout.
Number stamped on BB shell is very faint but the last few digits are ....702.

Hope this helps your worthy effort and that after collecting a bunch of data we can make some heads or tails out of it.
Thanks.