I'm out of my element there, but I can tell you that if you do put an American part on there, as soon as you are no longer in possession of that drum, someone will strip that part off in 2 seconds flat and the drum will be no better off than it is now.
My two cents: really try to do the best you can with the original. It will probably be the best for the value, collectability and maybe even playability of the drum.
Maybe post a pic of the strainer (front and back) and we might be able to help you with it.