Your pic of the bearing edge is interesting. Looks like a 60's Supra edge; for some reason, I was expecting the edge to be soldered to the side like on an old Brass shelled snare.
It would seem no big deal for someone to knock out a few special snares now & then; what's interesting to me is that, after switching to Ludalloy, they still maybe knew that their old brass shells were, arguably, better, & made their "special" snares out of the old stuff.
I'd lover to spend a Saturday in the old Ludwig factory with an old-timer, building myself a spun brass Supra. Would be a memorable time........marko