How to prep gutters for weatherstrip/glass installation

Getting geared up to get some glass back in my '68 fish. My question is in regards to prepping the front and rear window gutters prior to installing the glass and seals.

I was planning on (without a bit of research) cleaning the areas that needed it and then sanding down all inside and outside surfaces. Then after sanding is done I was going to spray with a self etching primer then hit it with primer sealer.

My additional question would be should I topcoat it after doing the primer sealer or would that be sufficient?

Thanks

D