i would not worry too much about stainless on 6063-t8
i just took down my i-10k after 12 years of use,
its never been cleaned or sealed on the trombone connections,
the antenna never had any issues with vswr changing over time or bad connections,
i never had any cb antenna up that long without needing some kind of servicing or fixing because it snapped,
my blind buddy up the hill still has his i-10k up 11 years untouched,
his sirio 827's used to last 18-24 months before galvanic corrosion on the coil connections made them go open circuit blowing up amplifiers or his president jackson final.
i just took down my i-10k after 12 years of use,
its never been cleaned or sealed on the trombone connections,
the antenna never had any issues with vswr changing over time or bad connections,
i never had any cb antenna up that long without needing some kind of servicing or fixing because it snapped,
my blind buddy up the hill still has his i-10k up 11 years untouched,
his sirio 827's used to last 18-24 months before galvanic corrosion on the coil connections made them go open circuit blowing up amplifiers or his president jackson final.