Looking for Tektronix S-6 Users with Working S-6 Sampling Head

[Electro Fan]

I tried to get my S-6 working but no luck.  It just dawned on me after looking at photos of various units that some are put together so that the push pin on the back is near the open round hole on the back, and some have the push pin opposite the open round hole - see examples of each below.  Any chance if you have a working S-6 you could check to see which version you have?

Also, it appears that in some cases the push pin lines up with the side that has the adjustment access hole; in other cases the push pin is on the other side of the case (opposite the side with the adjustment access hole). 

Just trying to figure out which orientation Tektronix intended....?

Also, if you have a working S-6, does the back of your unit have the Tektronix writing, or is the writing absent?

Thanks!