Couple of questions for some of you guru's

[CoreyGill]

I am in the middle of a 65 restoration and i had a few questions and after reading countless posts you seem to be the guys to ask.

I was thinking about molding the tail light panels and the bed, is there any reason that i cannot or should not weld and seal that seam?

Second question, I bought the truck with an aftermarket external transmission cooler. I had the stock radiator rodded out and flushed and while it was there they tested the bottom portion of the radiator where the stock transmission hooks up, no leaks. Would it be better to run the external cooler or move the lines back to the factory cooler?

Lastly, what do you guys recommend to polish trim? I bought the truck with all of the factory trim intact but it needs a little shine.