Topcor-S 50/2 needs cleaning

[Lightshow]

Normally I do this kind of work myself, but I was unable to get the rear element clean, so I thought I'd get a pro to clean it the right way, and maybe do a re-lube & one of the blades is a bit behind the others when stopping down.
The question is, who to send it to?

 

[Livesteamer]

Focal Point in Colorado, run by John Van Stelton, is very good. He has cleaned three lenses for me and I've been very happy with his work. Good Luck. Joe

 

[Lightshow]

Sorry for the late reply, I thought I already did...
Thanks for the reply, I'm now coming to the conclusion its coating damage on the rear element caused by fungas that has since been cleaned away, I see nothing in the pictures, I might just leave it as is.
Thoughts?