I haven't experimented with magnets and coils for a really long time, but I'd considered suggesting earlier that you might want permanent magnets rotating within a stator and coils. I wouldn't have a guess what the output would be if you'd take a simple AC motor's rotor (or make a new one) that is cut to accept some PMs. I think it'd be something like an alternator with a lot of stator poles.. maybe. One (probably odd/weird) idea that occurred to me was to reduce the diameter of the rotor, then machine some pockets into the rotor for the magnets, epoxy them in place, and slip a brass sleeve over the assembly.
I'm almost curious enough to try it, but there are so many pending projects already. I thought I'd mench that there are other small-value AC caps that're a lot more compact than the aluminum can type.. they're sold at places that sell replacement parts for ceiling fans.
WB .................