NEVER said that BBB cut the cannelures (or had access to cold blue)
We're speaking of a FINISHED part, and one which is completely interchangeable in seconds; the REAL question is - does it BELONG there or not? That's what I'd like to ascertain, and document for posterity.
As to the spoon cut in the stock, there are PLENTY of 1868/1870 2-band stocks without it. The real question (perhaps saving grace) is the single cartouche. That speaks way more than the spoon matter.
Also, is the inletting for the receiver long or short? Most people will tell you, even today, that SA made NO 1870-specific stocks in rifle length. That is NOT true - somewhere in my archives (from 50 years ago) I have a side-by-side 1868 vs 1870 inletting photo which shows that they did. The photo was taken by a dear friend, long gone, and, I handled the guns involved - the '1870' inletting was PERFECT (no BBB) just shorter. Sadly, I was just (1971) beginning to collect and did not note any other features of the two rifles.
I could not find the pic when writing my 58/50 book - I hope is isn't gone forever . . .