7 Piece Piston Ring Set with Heptagonal Tensioner???

Anyone ever see a set of piston rings like the set in the image below? The second ring has an internal hexagonal ring behind it and an extra steel ring below it all in the same groove. This is a new one to me. Any of you guys know more about them by chance?

That looks like a set of NHRA legal cheater rings back when you had to run the stock ring widths in the pistons, you could run a spacer in the groove to run a narrower ring or a gapless ring set.
The hex ring looks like it is a spacer tensioner to run a narrow width low tension ring in a stock depth ring groove
Maybe you can figure it out from the part number

I have a set like this , minus the hex tensioner, in my 383 set up for stock eliminator. Mine are from Childs & Albert about a year before they closed shop. Stock ring groove widths is the reason for this choice. 5/64"

Cab is on the money, as usual.

Cab, These came from that 413 I picked up so I don't know what brand or part number they are. Much to my surprise, they rebuilt this motor ages ago and never ran it. New pistons, bearings, etc. It also has a new Crower X31F cam in it. I'm thinking I'm going to clean everything up, put it together and give it a thrashing in one of the cars. That being said, any reason not to use these rings if I already have them? Where do these rings fall in relation to performance? Better than a standard set but not as good as a modern set?

No reason not to use them.

As for those rings against a modern ring...a bunch of the power found in modern rings comes from piston groove geometry. It's sooooooo much better now that it's not even close.

I'd run them and enjoy beating on it.