I have a tractor with similar "patina". I spary it with a little WD 40 when I think about it just to prevent deep crusty rust. I don't do it so much because I like it. I do it because thieves ***ume it's a junker that doesn't run. I've left it some really bad neighborhoods where I had jobs. I parked it in highweeds and never had a problem. I had a garage where people used to try to peep in the windows. Hornets built a big paper nest at my garage door. What a great deterent. Not only did people stay away; they ran away! The hornets seemed to get used to me opening the door. I never had one sting me.
The only combining is after the fact to make sure you have no DA divots in the finish. Some stuff doesn't matter, but I mostly refer to "prime" finishes in my replies. Good luck, and for the last time, CHECK THOSE PAWN SHOPS