I think mine are Parker Hale and set up for a 3/4" Pecar scope. The problem is that the Zephyr's dovetail rail for the front ring is not very long, so many front rings will not fit without the back half of the base sitting over the ejection port.

Quite a few people have asked me about magazines. I don't have a source, but if you should find one, be very sure to click it home properly so it stays put.