Originally Posted by benmacphoto
It could happen to any M6 as they were zinc plates. The titanium is just a finish, zinc is still below it.
Had a black M6 that had them, I just ignored it.
You are correct that M6's were made with zinc top plates, but I believe that the limited edition Titanium versions had brass top plates that were titanium plated.
M6's are know to display pitting due to the zinc top plates.
I kinda did a lot of research on Ti M6's because I likely own a rare prototype M6 that is a Wetzlar version 2 (with strap ring protectors) that has a Ti plating over what I would later learn is a zinc top plate.
My research revealed that my unusual Wetzlar has all the usual Wetzlar engravings, embossed Vulcanite, early metering, knurled metal rewind knob tip, Leitz Red Dot... but features a zinc top plate that is titanium plated. Oddly the knobs are all chrome and my serial number indicates that my camera was made about 5 years before the later limited edition was released.
I remember discovering that the Ti version had a brass top plate which further added notoriety to my prototype. I bought this Wetzlar M6 from Setadel Studios, the current sponsor about 9 years ago. This vendor seems to be located kinda close to the old Midland Leica plant, even though my camera was made in Germany.
It seems that my body chemistry has sped up the pitting and it also became more evident that underneath the Ti plating is zinc. My Ti M6 has a wonderful patina as somehow the Ti plating is kinda getting worn through in places, and then there are bubbles and pitting that are the result of chemical reactions.
The edges are rounder on my M6 when compared to my black paint MP which has more of a square to the edges.