I'm having trouble squaring the label and rim with the ring being either a conversion ring or original archtop (which I never heard of in this model).

I assume that conversion rings work with the rim as-is, no cutting involved.

If this rim was originally made for a flathead ring, why does the label extend above the top of the rim into an area where there would have been nothing behind it?

If the rim was originally made for an archtop, why was the label positioned so high the top of it extends onto the tone ring? Why wasn't it positioned lower so that it would be entirely on wood?

Rims made for archtops are taller than rims made for flatheads. On the original 70s and later flathead rims I've seen -- in person and in photos -- the label is positioned very low on the rim, even extending into the curve at the bottom, because that's the only way to keep the top of the label on wood.

To me, the position of this label doesn't look right for either original flathead or archtop. What am I misunderstanding about what I'm seeing?

I have no idea what the story is. But I owned an RB-3 Reissue several years ago where the label extended up onto the lip of the tone ring. And I've seen them extend a bit below the rim as well. The label guy having an off day, I guess.

Come to think of it, I wonder if the archtop ring found in an old Iida Japanese masterclone is what this might be. A friend had one years ago, and it was noticeably heavier than a standard Mastertone. And those StewMac conversion rings are pretty heavy as well.

I don't remember whether the S-M conversion rings had the holes. Seems to me they didn't, now that you bring that up.

Perhaps somebody else offered a conversion ring, too (can't think of anyone).

Then again, could someone have special-ordered it from S-M this way? They probably had the capability to drill the holes with precision as we see on that ring.

I'm wondering if there's a "maker's mark" on it in a location that can't be seen without taking the ring off the rim...?