As far as I know Finn has that pump manufactured for them and they assemble it. I don't think they buy that pump from a pump manufacturer. I do know who makes everyone else's pumps.
It is possible that you could have the pump casing welded to get you by but that would not be an option with the impeller. Repairing the broken parts is probably not an option.
I am sure with the situation with Russia hydroseeder parts are a problem. We were selling quite a few of our machines in Russia before the war as well and hopefully someday soon things may settle down and get back to normal.
The only thoughts I have would be to see if you could contact a Finn dealer in another area such as China, India or the Middle East. There is no problem with shipping to Kazakhstan. It should be just a case of finding someone who can ship you the parts.
We do have a Finn rep who posts here some and I will see if I can poke him and see if he can suggest any solutions. I may actually see him in a few days. I will be at a trade show in Baltimore next week and Ron should be there.
On a side note, you have a very beautiful country. I have seen a lot of photos of your country and the scenery is terrific. I came close to visiting Almaty about 15 years ago and would have really enjoyed that trip. Thanks for posting your question. We will try to help you solve your problem.