Refinishing black trim

[Otter74]

I have a pair of wiper arms with a bit of corrosion on the end of one that I’d like to refinish to look good and then install to replace the polished wiper arms currently on the car (this is for my BMW E12). Finish coat will be SEM Trim Black - I have a can, and it gives me the finish I want.

Plan first is to wire-brush everything off the bad area, then wipe with mineral spirits.

Would it be better to then spray SEM etching primer followed by the color coat, or an epoxy primer followed by color coat, or etching primer then epoxy primer then color coat?

Goal is not to have a NOS-looking wiper arm, but to have a consistent and durable finish that basically matches what’s on the lower part of the arm and doesn’t come off.