As we were re-assembling our furler with the Amel Martinique team, my understanding was they thought these bushings were very important.  It seems to me they would be, otherwise the inside of the furling drum  would rub on the swage, and be off-center from the weight of the furling motor. There would be a significant bending stress on the whole system where the foil attaches to the furling drum.

Unfortunately, we got all that together before we thought to measure, so I'm afraid I can't help with dimensions.  From a materials standpoint, either Delrin or UHMWPE would seem an excellent choice. If you need one pair, it would be just as cheap to make 10, and have a lifetime supply.

Bill Kinney
SM160, Harmonie
Le Marin, Martinique