A new addition to the list of project... many thanks Mike.
This looks to be an version 1 Pentax 6X7 that seems to have been given a factory MLU.  I could be wrong and this is an early version 2.

The documentation that I have is that version 1 bodies could receive mods to the finish piece under the viewfinder, advance lever style, film spool spindles.  I have no info about factory MLU instructions or changes or what other parts need to be modified to allow for MLU operation.

If this is a standard out of the box configuration, then the list would expand in types of variations.

The current list that I know of is as follows:

Original 6X7 1969  - Silver lens release and checkered spool latches and angled advance lever.


6X7 MLU version   - Black lens release switch, rounded advance lever and flip-out key spool latches

6X7 DoubleEx MLU- Double exposure button (factory Mod)

Model name as 67   - Black shutter release collar, black lens release, flip-out key spool latches

P67 DoubleEx         - Double exposure button (factory Mod)

This is almost a perfect broken camera to practice on except that it was broken and I again checked if it was properly seated in gear and it was not.  I do believe that one of the critical positions or state that the camera must be set to to begin shooting was not found.  Much like body B this one I'll call body C was at first sounding pretty harsh when I tried to cock the shutter and then checking if the film roller was loose and running it forward it had snapped into gear.