F3c with Airmaster prop

I am installing a 915 with an Airmaster AP340 electrically controlled prop.  I would like to install the Rotax external alternator, but the drive pulley for the alternator occupies the same space as the slip ring for the Airmaster.  I think I can machine the Rotax drive pulley to accommodate the Airmaster slip ring, but I don’t have drawings/dimensions for the pulley.

Anyone have familiarity with the F3c alternator drive pulley dimensions?  Better yet, anyone done the engineering required to make the F3c co-exist with an Airmaster prop slip ring assembly?

TIA,

Matt