I have found that the best thing to do is go to a reputable radiator shop and recore the radiator. I can tell you I have done this on a couple different units and the re-cored radiator weighs about 50% more than the original. Those Russian radiators are very thin from new. It will probably cost less as well.
I agree the Russian radiators are junk. Have had more than one rebuilt. They removed the mounting brackets and built a new one. Another plus is you are getting rid of the Russian radiator cap