Leica-R Elmarit 35/2.8 version

[MEPER]

Is this version of the Leica-R Elmarit 35/2.8 how it looked or is the lens put in kind of adapter?
I would expect such a lens to be a bit shorter?
It is probably just an older version that was designed like this?
What image quality can be expected from such a lens?
Probably at same level as a Nikkor-F 35/2.8?