318 Engine stumble

That is one way to solve the rotor phasing. Buuuut...

If the polarity is reversed, you run the chance of having erratic triggering of the HEI module, with spark timing jumping around, even if the rotor phasing is fixed.

The old points distributor is tempting, but certainly not without installing new points and condensor. I looked at the pix you posted of that and still cannot tell if the nubs on the shaft that push on the points' rubbing block are worn down or not... And certainly the wear on internal bushings is unknown.