If anyone has an 11" or 13" GE motor and has already purchased a PTO disc from SSB Tractors to match the splined output shaft, I have two adapters already machined and ready to be assembled with Spicer flange yokes. There are at least two different PTO disc hubs. These adapters are machined for the 10-bolt hub. It has a centering ring (that the actual PTO disc fits on) of 2.549", and overall diameter of 3.872", and the ten bolts are on a 3.25" bolt circle.
The adapters can be purchased as is for you to finish, or we can finish them for you. The flange yokes have to be machined to fit in the recess, and the recess in the adapter machined a little bit to receive the hubs.
I also have one more hub (the one on the right), already removed from a PTO disc.
PM me if you're interested...