Might try First Stop Guns (SD). I planned at one time to sell a couple of my single-shot Coopers and buy a Model 51 repeater on either .204R or .222 Remington, and they had more 51s available than anywhere else at the time (several years ago.) They post a lot of their Coopers for sale through the Guns America site.
The problem I see now, considering the current manufacturer, is the availability of magazines in the future.
Good luck with your search!

Last edited by RowdyYates; 02/04/24.