Martin,

You may want to look into ceramic coating the metal. Check out fit4duty.com. They refered me to Charlie Sisk of Sisk Riffles and to H and D Rifles who have switchd from teflon to the fit4duty ceramic coating. Seems to be the next generation for weather proof coatings. Cost is reasonable at something like $200 +/-. Both Sisk and H and D liked the ceramic coating a whole lot better than teflon for looks and for wear resistance.

Good luck
JPK