I was looking at them too. They are almost like the TRW pistons that I have. Trw lists mine at 12.4-1 with 114 cc cylinder head. I 've managed to get my compression down to 11-1 using 119 cc combustion chamber heads and an .039x4.345 diameter head gasket(ROL). You could probably get it lower using a Felpro 1027 head gasket. They measure .039x4.370. With the cam I'm running I have a DCR of about 8.3 which is acceptable for 92-93 pump gas. My compression test is 190 to 200lbs.
I haven't had any detonation problems with that octane.
I'd get the heads cleaned up in the combustion chamber and pocket ported. That will remove any hot spots in the combustion chamber and unrestrict the valves. After the block is bored check the volume of the dome with the piston in the bore. This is what I followed to check my pistons, I dropped my piston down .750 (3/4 of an inch) because of the dome height:

For pistons with domes---put a top ring on the piston, wipe some grease around the cylinder and bring the piston .500 from the top of the cylinder (on the flat part, not the dome).
Measure to see how many cc's it takes to fill that area up.
This gives you the volume of the cylinder minus piston dome displacement.

NOW to figure cylinder volume without the dome use this formula...bore x bore x .500 x .7854, now convert that to cc's by multiplying it by 16.387. This is the cc's of the area without the dome. (like a perfectly flat top piston).

Subtract the answer from the first formula from the answer to this last formula and the answer is piston dome displacement.

If you click on my link below I have a picture of my pistons.

 

dirtrocker, If those pistons are un-blemished/damaged you've made a great buy. One of the best mid to high range pistons available!