Neoprene Bumper Repair

So I've been in the process of painting my car, body work, for over a year now. Well it's almost done. I've only got a few spots to touch up and then the color coat goes on, I hope, thursday or friday. I'm working over my fiberglass hood right now.

Of course there is one part of my car that I'm not sure about, and that's my bumper. I've got a 73, so my bumper's got a neorene cover on it, and it looks like crap. It's pitted with big chuncks missing here and there, and the old paint is all cracked up.

So I've got this stuff that's basically plastisized body filler to repair it with. I figure I need to scuff the bumper, slap on a layer of that filler stuff, get it smooth (sand it down again), primer it, and then sand it again before I spray the color coat. Boy my right arm is going to be huge.

Okay so I guess I just want to know if that sounds right or not, and if you think it will turn out looking very well. I'm tempted to just purchase a new bumper cover, but I've never seen one for sale anywhere, so that's out of the question.

Oh I'm going to put a flex agent in my primer and paint when I spray the bumper, and maybe the hood since it seems to flex alot at speed.

Thanks