Meyer Telemegor 300/4.5 - help in disassembly ?

[luisalegria]

I just got this old monster in - the thing is rather worn, so it looks even more like a piece of drainpipe than usual !

http://farm4.static.flickr.com/3330/3218949683_fdce41ff74_o.jpg

Its got the Exakta external flange mount, so my old Exakta->PK trick won't work. I have to figure out another way to make an adapter. Also, the rear glass is dirty, and I want to get at it properly to clean it, its very deep in the lens away from the mount. I want to remove the rear barrel with the lens mount.

So, how do you disassemble this thing ? I'm stuck.

So far I have removed all the screws on the tripod collar, and the stop-screw inside the barrel under the collar -

http://farm4.static.flickr.com/3379/3218949789_4baccdf89f_o.jpg

And I have loosened the big screw inside the tripod screw hole - removed it really.

http://farm4.static.flickr.com/3495/3218949975_f19e9162fd_o.jpg

I can unscrew the whole tripod mount ring quite far forwards and backwards on the lens barrel, but it stops short of anything interesting both ways. If unscrew it towards the lens mount, it reveals two screws near the focus ring -

http://farm4.static.flickr.com/3486/3219800784_5739902cc7_o.jpg

Not quite enough to unscrew them. And I suspect that, because there are just two of them, they actually hold the slides of the helical mechanism, and I don't want to play with that.

Any ideas ?