Urethane Bumper repair

I have a urethane bumper for my 71 Fastback, and it needs a bit of cosmetic work on it. It doesn't have any rips or tears, but it's got a few small nicks in it, plus where a previous owner did some light sanding on it (probably to remove some corner nicks as well).
My question is, what do you use to "touch up" the urethane (to fill in the small nicks)? I have done sanding before on other urethane bumpers, so I am familiar with the shaping after the repair...I just don't remember what to use to make the repairs...anyone here know of/or used anything that they would recommend?
On the same topic of repairs, I also have a spare trunk lid for my Fastback as well (don't really need it, but I know it's a bit harder to find them when you need them ) and it's cosmetically nice on the outside, just needs to be stripped of it's God-awful faded and oxidized purple paint!), but on the inside, you can see the rust, and when you move it, there is a lot of dirt and rust flakes falling around. So question number two here is, aside from sending it out to be dipped, any suggestions on how to handle this (I think I know the answer will probabaly be just to get it dipped anyway, but I like to explore my options)?
Thanks for any and all suggestions!
Mike

Worked in a body shop many years ago and the local paint/body shop supplier had some stuff that looked like a liquid silly putty. You would just mix it up let it dry and level it off. Seemed to work well.

5851a,
I know, I worked in a body shop years ago too...but I can't remember the name of the stuff, and the local paint supply shop hasn't any clues either! I tried a local body shop...but they won't reveal the secret ingredient!! They want me to just bring them the bumper for repair...go figure![img]/phpBB/images/smiles/icon_lol.gif[/img]
Mike

The owner of the shop I worked at passed away, I'll try checking with one of his kids to see if they remember.

Talked to the son and he can't remember. Try a paint/body supply that carries a lot of 3M stuff.

3M makes a product. I bought it at a paint store for my 73.