I agree with most of what you've posted. Nothing is gained by comparisons to catalog cuts, or even other guns. So many differences, many of them small.

It's just the two different 'hands' that have engraved the small amount that appears on this bbl,,and that matting,,that jumped out at me right off.

You're correct though,,more & better pics are needed.
Until then,,we speculate, question, guess & discuss. Part of the fun of it.
As you say, the 'sport'.