Hi Bill,
Unfortunately, I had no knowledge about the original source of these picutres. I received them from a friend who build scale models of vehicles used by Red Army as a curiosity. I am sorry having put here some questions which were already discussed here some time ago, I am quite new on this forum.

Greetings to Georgia, Jan. :salute:

Hi Jan:

Don't apologize my friend, you have brought new questions and new knowledge to this group.

I found those photos a few years ago on an Estonian site, no doubt the same one your friend found them on, and posted them on another website/forum, not this one. As I said, I can no longer remember which website and it has been some time.
In any case, several hundred new people have learned something of interest.
Bill

For comparison, a rear bogie from a Studebaker US6: