I would suggest that some or all of the tensioner / butt end is not original. I have a few similar era snare drums with a different type of butt end.

And they screwed it in waaaaaay too tight.

Looks like it may have been dropped on the butt end tensioner and that indented it. Had that happen to one of my Acros when I set it down too hard (ok I admit it, I dropped it) while in a soft carry bag. It is repairable !

If you take off the hoops and heads, the lugs around it and the butt of course, place it onto a hard rubber pad and use rubber mallet, you can softly bang out the indented area, you need to go slow and with soft tapping to get it to pop back into shape. Depending on the depth of the indent, you may also need yo use a small wood block (round) to get it back to its right place. I do not suggest heating it with a torch to get it to move easier like other metals as that will blacken and ruin the chrome.

Michael

It's definitely a Gretsch drum. I wouldn't worry too much about the hex head on the tensioner. Likely the original got stripped and that was the most readily available replacement. Also a slight chance that Gretsch put that on at the factory, perhaps getting the wrong part from a supplier or running short of the ones with the normal knob. At the time no one was likely to notice or care about such a detail.

I believe the original style Lightning throw off like you have there was only used for a few years from around 1968-1974 before they went to the newer version with the center handle. With the SSB badge coupled with that throw off I'd say your drum is from roughly 1970, which would be right around the time Gretsch drum production left Brooklyn for Arkansas. That might also explain the oddball tensioner as there were some construction anomalies associated with that move as they had to get things sorted out.

Thanks for all the feedback everyone! Very insightful. I decided to disassemble the drum altogether. All the hardware is in really good shape. Someone must have dropped this drum a few times or something because there are quite a few other dents around the throwoff and a couple lug locations. I'm going to very carefully try to hammer those out (rubber mallet of course) and shine her up. Can't wait to hear it with new heads and snares!

And all you owe us is pictures when you`re done.