Summilux to EOS compatibility confusion. HELP

[Darioratti]

Hello, and HELP!
A compatibility query regarding the various production years of the summilux 50mm 1.4 R with a 5DmkII
According to the pebblepalce.com data base the compatibility isn't very easy to comprehend.
Catalog No. 11875 & No. 11776 are of uncertain compatibility. These should correspond to production years 1969-1986 and are all first versions.
No. 11777 is compatible and corresponds to production years 1986-1997 and is the first version.
No. 11343 is of uncertain compatibility. It corresponds to production year 1997-2000 and is still fa first version.
No. 11344 most probably only needs O-ring removal (?) from the rear optical element to make it compatible (again-?). It corresponds to production years 1998-to present moment and is the second generation.
Main questions are:
1) how do I deduce No. (ie catalog number) from the serial number of the lens?
2) does anyone have any information of the "uncertain" compatibility no.'s 11875, 11776,11344 & 11343?
3) anyone have any experience with the O-ring removal of No.11344?
As always thank you

[pirius]

I have E55 version of it (first optical formula but with built-in hood) and E60 version and I haven't noticed any mirror issues on 5D II with either. But your mileage may vary.

[Darioratti]

I do understand that I'm in the process of making an utter fool of myself, but what is E55 and E60 with respect to catalogue nu,beer and serial number?
Once again thanks in advance

[pirius]

That I don't know for sure. E55 probably started around 300XXXX and E60 around 370XXXX. Try here: http://www.forloren.dk/lbf/leica_lens_serial.htm
and here: http://www.antiquecameras.net/leicarlenses.html

E55 is very easy to distinguish from the previous model as it has built-in hood and the first version has a separate hood. E60 is just like E55 only bigger and costs over $2k

[Orio]

I used to have the second-to-last version of Summilux 50 (now sold to a forum member) and no problem what so ever for me on my 5D Mark II.

[Darioratti]

Seeing I was in doubt, I purchased it all the same
It's a summilux 50 1.4 serial no. 2901740 and I've got a leitax conversion mount coming in with the post over the next few days.
I'll just see how it goes.
Thanks all the same