Ron (Netherlands)
Well-known
No wonder they're so hard to find, you have them all!
However the collection is not complete yet, what you see is:
the genuine M-mount is one of the last made in 1968,
the genuine LTM is from 1962,
the convertible (so M/LTM) is from 1960.
All three have the small red dot, the convertible has a feet scale starting with 2'4", the genuine M starts with 28" and the Ltm of course with 3'4".
What is still left:
an early Summaron with a big red dot (might be that the big red dot type combines with different feetscales, but I am not sure yet),
a Summaron with goggles (the M3 type). The type with goggles can be found with early 2'2" feetscale or the later one with 28" feetscale.