How to mount an old original Nexstar 4 silver tube

A relative gave me an old Celestron Nexstar 4 silver tube model. We estimate it's probably from the late 90s. The go-to mount is fried and unusable. Celestron service stated the scope was unrepairable due to its age and incompatibility with parts for the orange tube SE models. The optical tube assembly was removed from the broken go-to mount.

The dilemma now is how to use the unmounted scope with a tripod. Online notes state the tube for the Nexstar 4 (not an SE) has a 127 mm outside diameter. I cannot find anyone selling a tube ring in that size so the scope can be connected to a Vixen mount to use as a spotting scope.

Does anyone have any recommendations or know of places that sell the accessories to allow the Nexstar 4 to be used as just the standalone scope?