You might try getting in touch with Century Arms Int'l, I read that they often have small amounts of more specialized guns that don't get listed in their flyers. If you sweet talk them, they might find something in particular. I know Remington made M91's, and I think Westinghouse? Anybody know the second US maker for sure? Also try Tuco's Gunboards - they have a trader section and they have a lot of very knowledgable Mosin people.