A couple of good machining magnesium images I identified:
F-8 Crusader
Image by wbaiv
The back of this F-8 has been stripped down to bare metal. Some of this is very perishable magnesium, some is fiberglass, some is aluminum, some stainless steel.
102-0287_IMG
F106 procedures trainer DSC_0665
Image by wbaiv
Note right side console cover/structure is bare primer. Its achievable a ‘live’ procedures trainer, really in use, may well have a cockpit piece in-primer, but I’d be shocked if an active duty F-106 was left hunting like this. Not impossible, but it appears unlikely. Appropriate paint worn and scuffed down to primer? Certain. Provided the paint is not covering some magnesium bit or other simply corroded item. "Mission-essential" paint would be maintained.