If you want a 7X57, you can get the MCA model or others that were made from 1950 onwards. They moved away from the split bridge design (to the one where the bolt locks behind the bridge)in the late 50's or 60's.

The 6.5X54MS is a classic caliber & you can get Greek Military rifles for a cheap price & customise them as sporters. They are not as common now as they were 20 years ago.

Good luck.