Questions for Linhof fans

I recently bought a "Linhof 4x5" on e-bay which turned out to be a pre-war Technika III 13x18cm which had had a 4x5" Graflok back grafted onto it.
I now see another one on e-bay:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=7527843781&rd=1&sspagename=STRK:MEWA:IT&rd=1
I am curious to know - were a lot of these cameras converted? Do any APUGers have one?
Another curiosity - the e-bay camera comes with a 135 lens in a RECESSED panel and a 90 mm on a FLAT panel. I presume some one used the 90 mm by putting the lens standard on the back (fixed) track and pulling and pushing it to focus. As far as I can see, you can't really use a lens on a flat panel of less than about 115 mm focal length - or does some APUGer know of a way of doing this? And is there any source of lens panels for 13x18cm/5x7" Technikas, or do you have to go the DIY route?

Regards to all,

David

I had a III with a IV back... I also think I have an original III back for single-sheet holders...

135mm lenses were often in recessed panels to give the same infinity setting as the 150mm lenses. I used a 90mm on a flat panel on my III 5x7" by putting the standard on the very bak of the front rail, then dropping the bed and pushing the whole rail into the camera body. Worked just fine - at least with a 90mm f:8 SA.

Lens panels show up on german ebay once in a while; and no, I don't have any spare.

The 135mm Planar is in a recessed board so that it fits when the camera is closed, and it just _barely_ fits. My ground-glass has a ring mark from the few times I pushed it in just a bit too far. I never thought about the issue of having the same infinity stop as a flat-boarded 150, and wonder why it is important when there is no rangefinder. (You can put as many different infinity stops on the bed as you like. I have four.)