You can't complain about any of these. It is clear that composition was pretty much at the forefront of all of them

Provided you haven't touched the SD card since, you can recover them. The more you use it the less chance you have, so remove it NOW.
Look up Wondershare Photo Recovery on the net and follow the instructions. It's idiotproof and it works. It also has the approval of Kaspersky Labs as a respectable program so you can install it with confidence.

This one also is not a native M42. The Russian designation (say) Jupiter 11A or Tair 300A would indicate that it does indeed have an interchangeable mount and you can replace it with a Pentax K version if you so wish. The suffix 'A' is the giveaway.
Should you ever do so, DO NOT undo the grub screws completely (you'll never get them back in !) but only sufficient to release the mount ring and get the replacement on. ............ I learned the hard way !

They are indeed great places to take a camera, as you have demonstrated - #2 really takes the pumpkin !

I really like that picture

These rails make a big thing out of being exquisitely adjustable- -often in two planes. I've got one of the "Newer" ones. They work fine but they don't like heavy DSLRs sitting on top of them (and remember the whole ensemble has to sit on top of your tripod, making for even more wobble).

I currently use a vintage set of Pentax bellows for close work, which will be absolutely ideal for what you want to do. The loss of the lateral adjustment is irrelevant. You assemble it and plonk the tripod where you want it and make your final framing adjustments by physically moving the platform supporting the thing being photographed. Then magnification is done by setting the extension of the bellows and focussing by either moving the front support or (if you've got one that allows it) by incrementally moving the whole unit back and forth, using the screw. Perfect for any tiny object and for focus stacking.

Here is a result



and here is how it was shot. *istDS, pentax bellows, beat up takumar 135 (note the working distance)



Start with a cheap Russian set off Ebay and keep looking until the right Pentax one comes along. In fact I've got a good, boxed M42 thread Pentacon style set that you can have for a fiver + postage !

I must admit, I was quite surprised when you decided to sell them - mine are priceless

Thank you for the firmware link -- job done

They clearly don't want to go North do they?

IS there a firmware update for the K-3 II? I looked on the Pentax website and could not find one -- or have I missed something somewhere?
Batteries have been fine. One Pentax original (supplied with the K5) and an Energiser so far. I haven't charged the new one yet.