The old FireHawks are now a meat and potatoes gun but back in the day, they were top notch. They still are top notch imo and very close to a MK85 in build quality. Its a great gun to carry all day and just plain feels good too.
My old Firehawk SS 54cal (sold to a friend) is still going strong and IIRC it was bought soon after the SS was available. I can not begin to tell you how many rounds have been though it and it still shoots like a champ.
Back then i did not know any better and used bore butter on patches and dried out conicals. I think i kept it stored with regular gun oil or Ballistol but i cant remember.
The odd part is....now it shoots T7 for a friend with very low crud ring build up. It can be loaded 5 times easily. The crud ring is also much easier to remove?