I run a little repair and restoration shop, and have encountered several fridges that failed in the same way this one did. The modern copper lines are so thin that the refrigerant leaks out of them within five or six years.
I checked this unit for leaks and found no large leaks, and then I installed a service port. This made it very easy to replace the refrigerant. I added extra refrigerant and so it should last three years at a minimum.
I also lubricated the condenser fan underneath so it runs quiet.
This uses the newer r600a refrigerant which is very inexpensive to replace. I hope to be available for many years if you need this serviced, however another refrigeration technician would find it very easy to service now that it has a good quality service port installed.
This unit is a commercial model refrigerator aimed at daily use at bars and restaurants. I restored it in the hopes that someone could avoid taking a gamble with new units and instead have a unit which is easy to sustain.
I hope to continue running tests on it in my shop to detect any leaks. By using a thermal camera I can check the levels of refrigerant in the coils during operation without having to open any service ports.
Please let me know if you want this for your restaurant. I'm also open to partial trade for other broken equipment I can restore.