Need help identifying and then finding one old Mahle 89mm piston!

[Cornpanzer]

Ok, so this is a real needle in a haystack.

I have FIVE 89mm Mahle pistons. Initially, I thought that they were Euro RS pistons, but they are not.
If you notice, the valve pockets seem to be deeper and the crown higher than a 2.7 RS Euro piston. I suspect that they are the Mahle 2.5 short stroke competition pistons as uses in the GTU class back in the 80's.

Can anyone confirm this for sure and even better, does anyone have a stray piston that they would sell?