I wouldn't worry about gumming up the works, krylon is fairly thin. If the South African FAL camo jobs don't gum things up a whole can of kyrlon wont.
Base plastic is black? Means scratches & wear will end up that color, another part of the camo.
My only camo job has a few things here and there but crap it goes out to the range every time and is 6-7 years old now. Mine gets extra camo since my base furniture was sand color. Krylon and testors paint.