Tanar 35mm f2.8 lens

I picked up a Tanack IV-S, which looks like an interesting backloading Barnack/Leica clone, but the main interest was the 35mm f2.8 lens it has on it. Anyone know anything about this lens? Seems to be pretty rare and not much of the web about it.

Information found here:

http://forum.mflenses.com/tanaka-kogaku-tanar-35mm-f-2-8-ltm-t70998.html

The 6-element in 4-group makes it a classic double-Gauss, very similar to the Leica 35/2.8 Summaron and Nikkor 3.5cm F2.5.

I have the Tanar 5cm F2- which is very close to the Nikkor 5cm F2. I also have the much more common 13.5cm F3.5, similar to the Nikkor 13.5cm F3.5.