Maybe the rifle is built on the same idea as the Yugoslavian M95M conversions in 8x57 using a sheet metal insert captive in the magazine in place of the ammunition enbloc clip.

The insert stays in the magazine and allows single rounds to be loaded into the mag. The over the bore scope mount wouldn't be an issue. The magazine still uses the M95 original follower arm and spring.
Would work perfectly for the 7x57.

Looks like a great rifle. I'd buy it in a moment for that price.