I was able to wander up there today, and with a few pointers I received in PMs (such as 400 grit sand paper to get rid of burrs)(and cleaning afterwards), as well as something proper to drive the seal in I put in without too much more trouble, bolted everything back up, and she's running well. I changed the oil (it needed it) while I was at it as well.
We'll know after the first good snow if putting the seal on the other way around fixed it or not. It runs better (at least to my ear!) with the distributor shaft replaced. Much tighter unit (no wobble) should help.
Thanks again all!