Stop in for a cup of coffee

Generally all synthetic /alkyd enamels will be fine, once fully cured 2 to 3 weeks is my guideline.
Oil based primers can be cut with urethane grade reducer too or xylene and acetone.
Many I know will use rusty metal primer, followed by fillers and urethane primer surfacers on top.
When in doubt test a small area, if primer ain't fully cured or solvents too aggressive can and will bubble.
Good luck
I think for me, I’ll just try to match everything to be the same base type. Being a rookie and all