Your cab has a metal CP, mine was wood, so the following might not apply..
Under the CP attached to each side (inside cab) is a scrap of wood the locks are mounted to. The few cabs I have seen they were cut from scrap material the sides were made of so blue/orange. They would be the least faded to use for color match, but might be difficult to remove & take to the paint shop. I think they are just pin nailed in though.
As for the FIFJr vs DK, I started building a FIFJr bc it gives me a second button without looking out of place on the CP. Visually though, I'd rather build it out as a DK or even back to Popeye and lose a button.