Old Zastava SXS doubles from the 1960s were rather nice. Then they changed blued receiver to silver, simplified the bolting, used lesser wood, etc., calling it M75. Still not a bad gun but with a somewhat cheap look to it. Chambers are 70mm. If anything breakes just write a nice letter to the factory and hope for the best; much better chance compared to thousands of old guns with their factories long gone.
Regards
Jani