Complete grill sections were disassembled, all the black mounting frames were replaced/repaired and refinished. Each aluminum part was stripped using Easy Off Oven cleaner, then sanded down with 400-2500 grit. Then polished using 4 different compounds on buffer wheel. Final polish with Autosol polishing paste.
Still have a few spots I need to go over but, overall, I'm satisfied. After all, these are 50 year old parts!!