to further prove my point, i'll post two photos of a 1911 that this guy had.
it's a US Property marked milspec 1911, date of manufacture and serial number are already indistinguishable. how do you think rust was like on this pistol? well, this is what the owner, John told me:
"Here are the photos of the US&S with all the pitting.. It shoots just
fine!!!!!!!!!
John"
true, it's not a Glock, but it's also a near 100 year old design on a pistol. Glocks are supposed to have excellent corrosion resistance, and they pride themselves for making firearms like that.