Hello Alan, no Sonor expert here either

To me based on what I have on my floor tom those lugs do look authentic

I have not seen that type of leg bracket but the wing bolt on it does look like Sonor

I have been looking at parts for a tear drop kit and generally they are expensive

It all looks Sonor Teardrop to me. Those leg brackets are early 70s I think, but I'm no expert either.

Parts are expensive and hard to find.

1/2" out of round is pretty bad. I've heard of people correct warped shells by placing threaded rods from lug hole to lug hole all around, and forcing the drum into round after wetting the wood, then having it dry in shape over a mild source of heat. Then repeat, and repeat, until the drum holds in the round.

It's teardrop. but it's franked I think. The top lugs look like the newest version of teardrop and the bottom lugs (Commonly removed for C-toms) look like the shorter thicker older one's. The leg brackets and legs are Champion series and were used on the last of the teardrop run.

It looks split. Probably why it's out of round too far. Vertical seams do not exist on teardrop six ply interior SONOR drums, they are veneered diagonally. The "seam" on the exterior is too much and looks like a split as well. It's very hard to find a seam on any SONOR drum with six or more plies. They went from logs to drums in the factory from the sixties and back. Lugs went from ore to product as well. Very talented woodworkers.

Tap it all the way around to see if the tone goes dead near splits/"seams"

Oh, it's six ply beechwood.

Based on stated measurements the drum is 1/4" out of round. Possibly not too much on a 16" diameter. Head fit will determine play-ability if shell is otherwise sound.

Thanks Oddball!

It actually has multiple seams on the exterior, two straight and one diagonal seam. (Photo 1 shows one straight and one diagonal next to each other--other straight seam is in original post-photo 1). Only one straight seam is visible on the inside.

That looks like fill before wrap on the outside. The bookmatching isn't so uniform as long as they are tight. It'll sand smooth but not true. and the inside one will sand away true like original. There should be three digits in it because that shell isn't early it's last run. Does it have edges that taper from a center ply back both sides ? or Does it have rounded that way too.

Are all the lugs the same ? Look at the necks, that's the obvious difference. cuz I'm seeing the same on bottom now. one or two replaced gets noticed later.

The only way to get that interior back to factory is to spin the shell and hold the paper. Then clear it.