Hi Mark
Interesting query. I have just noticed how corroded is the air filter canister on my early 1968 280SL auto and decided to clean and paint the the lid. My latches look every bit 46 years old, but I won't replace them. Rather, I think it probably best to retain the originals. At most, I might just prime the latches and apply a couple of spray coats of black paint to them.
Regards
Philip French
Tunis Beige Metallic 1968 280SL Auto
Sydney