I think both of yours are Slingerlands, one is from the '60s and one from the '70s. A quick way to tell, is that the insert on the newer ones tick out pretty far...while the tension rod inserts for the older one just stick out a bit above the lug itself. "70s ones are pretty easy to find, so I wouldn't put a drill to the drums. Sometimes you can slowly work the older ones into the newer holes as the space difference is real slight.

[COLOR="DarkRed"]I would concur...if the right one isn't a later Slingy, it's a hecka good knockoff, actually....[/COLOR]

The one on the right won't fit a 70s shell, so I'm going with knockoff. And it is a really good knockoff at that. Those posts on the back side being weird are about the only thing wrong. The others were the standard metric threaded lugs where the two dimples on the front aren't quite as deep as the real thing. The one in the picture is damn close though.

FYI, the inserts on both don't but just peek out of the top of the lug ala the older lugs.

Hello, I think both lugs are Slingerland but the one on the right is probably late 1980's or newer and a Slingerland imported lug. I've noticed the mount patterns of the imported lugs (at least some) are slightly different and don't quite fit vintage holes. These lugs are lighter with a thinner black spring. The bottom of the insert (hex shaped part) is also thinner and (I think) sometimes square.