I guess most of us have a "That might come in handy" box as I do. I found this dishwasher pump that I had thrown in and it looks like it will be a good fit to replace the internals of the old motor. A slow turn showed voltage on the multimeter.
WHY? That old motor looks so cool (the guts, but not the existing bell housings). Have you found that field winding of the stator to be shorted or grounded? Insulation on these old motors last, if they were not left in total uncontrolled moister conditions. If you made antique looking bell housings with large openings, that could display the windings, that you can paint new insulation red-oxide enamel Glyptol is a trade mark name in the USA of such a product. It's universal to painting on motor windings, I've seen it in spray cans. But I would first use a tooth brush and dish soap and water to clean the motor coils up. They may be fine with the aged patina and you can see if there's cracked insulation.
That new motor hidden inside the old motor, still needs to be converted to a generator.
I know nothing about how to do that, or if just putting permanent magnets on a new rotor or your intended machining grooves in the existing rotor will produce enough flux to produce the desired voltage output, but I assume it's a 220-240VAC motor, and that should work.
Looks like you tried to arc the slots closed where the induction motor shorting bars were?
That silicon steel of the rotor with stick rod filler, what Rockwell hardness did that produce? Still looks like the right way to go for antique coolness factor without stick building everything from scratch. But to mill hard steel, needs ceramic end mills, coolant, and a rigid milling machine. You could build a new rotor, with as many even count slots you can machine in that diameter and magnet size you want to fit in.
Your motor looks marvelous!