Your making me blush guys...lol...

Can you yellow the new bumper caps a little with some clear cote of some kind at all??

Also....was thinking about just touching up the red only on the cab???Or would that not look any good as its only the red thats faded big time...

There is nothing that brings up a playfield more than a new set of repro caps - PBR sells them. Leave them white and while you are at it buy and replace the skirts and bodies.