Here is a rotor I finished last night.
It's a Delco out of 1986 Camaro, not sure what series it is but I think it's 100 amp.
I cut the shaft and replaced it with n52 3"x 1" disc and n45 3" x 1/8" disc to get the get the same width as the factory core.
Then I glued it all together with JB weld.You probably need the jaws of life to separate these but the glue keeps the two rotor halves from twisting.
It was not easy to make but it only cost about $60 in magnets and is one powerful rotor.
I made one out of a 10dn a while back and it peaked out at about 130 watts with 5' rotor and 6 high speed blades and guessing 25- 30 mph wind gust.
And I think I wound one of the phases bad because it didn't put out like the other 2.
Whith the factory stator, cut in speed was around 500 rpm but I wanted it lower.
As you can see the one stator is much smaller.
I plan on making a second machine with factory stators and connecting the rectifiers in series to hopefully get a decent cut in speed.
So I agree, get rid of the factory set up and go with a good powerful ring or disc magnet.
Its a little work and you need some tools but it will put out some useable power.