Can you identify this carbide insert?

[bakrch]

Yep, looks like a shim seat for this type of tool.

Seat installed.

TPG insert on top

chip breaker on top of that.

and finally the clamp. I don't think anybody has used these here in the shop since Oscar retired a few years back. Believe it or not, I cleaned this up prior to taking pictures, haha.

 

[Dynahoe Dave]

It does look like the Kennemetal parts in the picture above.
It is .125" thick.
And wow, that's a stack of stuff to make the Valenite holder work!