M240 observations & questions

[RFH]

Last update to my thread: I stumbled upon a 6-bit coded Summicron 35 ASPH at a too good to pass price. What a great lens - razor sharp from edge to edge. No resolution issues, either.

 

[RFH]

For what it's worth, and for the record:
My local Leica repair place were unable to fix the issue with the lens. They sent the lens to Leica and picked up most of the tab, which was significant. A nice gesture on their part.
It turns out that, among other things, the retaining ring I suspected was missing behind the front element really was. What ever happened to the retainer to make it go missing is anyone's guess. Some aperture blades were bent and had to be replaced.
Now the lens is tack sharp even at f2. I'm happy.