Excellent ideas and I thank you for the consideration.
Having considered everything, I'll buy two undersized couplings and tap them as appropriate. As JJPellin suggested, I'll grind a flat spot on each shaft for a set screw so the threads are not continually tightening since both are R-hand...
I'm having some trouble finding an acceptable solution to direct coupling of an M8x1.25 Honda mini 4-stroke engine shaft to an M14x1.5 alternator shaft. I'd like to couple them end to end since the RPMs will be well-matched to obtain the output I'm expecting.
There are many spider couplings...
