Dirty/hazy finders, ‘dry’ running shutters, inaccurate shutter speeds, general dirt, dents, light leaks,etc. A full general overhaul (CLA) includes at least: removing dirt and old lubricants, greasing all moving parts with the corresponding, different lubricants, check/replacing light seals, cleaning finder, check general technical functions (speeds, shutter, finder, self timer, flash, etc.) and of course adjusting.

Shutter curtains will be replaced if they are torn loose, deteriorated, porous, stiff or dried
out.

Fungal affection (haze), play, badly running (focusing)helicoids, aperture handling, dented filter threads/lens hoods, etc.

Of course badly affected or scratched lens parts can’t be fixed. The result of the cleaning depends on the extent of the (fungal) affection, but normally a lens benefits from a good cleaning. And, more important: the process will be stopped.

A full general overhaul (CLA) includes at least: removing of possible haze/fungus, cleaning & sterilizing lens parts, removing dirt & old lubricants, greasing of the (focussing) helicoid, cleaning of the aperture system and of course adjusting.

(The mechanical parts of) your digital Leica M can be CLA’d: a CLA includes greasing & adjusting the shutter advance system, adjusting the manual speeds & automatic exposure mechanisms, cleaning & adjusting the viewfinder/rangefinder and sensor cleaning. 

Your (older) M-lenses (Leiz, Zeiss, Voigtländer) can be 6-bit coded for the use on the digital Leica M. Lenses can also be modified to bring up the right frame lines. A new bayonet is not supplied and fitted; the six needed slots will be milled in your existing bayonet and painted (black/white) according the Leica coding list. If a lens is not on the Leica list (f.e. older Leica lenses, Zeiss, Voigtländer lenses), it will be coded according to the Leica users forum list.

Sometimes Leica equipment arrives in a ‘sad’ cosmetic state at Kamera-Service. In general, a lot can be done about that: panel work, replacing covering, touch up of lettering, replacing red bayonett-dots on lenses, replacing film speed indicator tags, extensive exterior clean ups, etc.

During a CLA a polarization filter can be placed internally in the finder, this eliminates ‘flare’.