I HAVE SOME 914-6 SPACED REAR CALIPERS. THEY CAME WITH A SET OF WORN OUT ROTORS. THEY GUY SAID HE DID NOT KNOW WHAT MODEL 911 THEY WERE FROM. THEY ARE DOWN INTO THE 17MM RANGE. THEY ARE FROM A CAR THAT APPEARS NOT TO HAVE PRAKING BRAKE SHOE OR ONE THAT USES SMALL ONES.

I HAVE A 944 THAT I AM PARTING. THE REAR ROTORS LOOK LIKE THEY MIGHT POSSIBLY WORK. HAS ANY ONE TRIED THESE? THEY HAVE A WHEEL CENTERING HUB ON THEM.

early 911 rear rotors

You want the 20mm 911 rotors not the 24mm from the later years.
You may need spacers between the hub and rotor to get the proper spacing. I make these spacers, and the thread can be found in the resources section to see photos.

Resources link

You may also need to reduce the diameter of the 911 rotor. They are bigger diameter than the 914/6 rotor. This would reduce weight, momentum and the ring that would result from the unswept area.