IIRC, this looks like the same truck that was for sale in the last year or so as an incomplete project .
The ad does say it was a "M" originally and the doors were added. Many of the pics would seem to support this. The truck has all the original cleats for the soft top and the new tops doesn't use any of them. The latch jambs behind the doors do not appear to be made of the structural (or rigid) metal common to all K's. For the life of me, I never remember seeing a Swiss spec 712K through all the years of the Thun auctions...??
One of my main concerns would be if longitudinal structural supports were added to the body where the door openings were cut into the pan. The folds in the M's sheetmetal adds lots of structural rigidity.
Thank you Andre... I was extremely happy with the way the Pick Cow came out... just shoot me if I ever think of trying that to GG.

.
The Trojan Horse... the 1st Pinz used to covertly carry troops into battle .
ATL Pinzgauer XM 718K TUM(HD) 6x6 FFR (aka The Green Grail)