FYI, the turret ring that is included with the new Tamiya display Leopard 1 kit is the same part as the Tamiya Pershing turret ring.

The new display Leo 1 kit does not include the 3 turret rollers but does have the 3 stand offs to mount them on.

I can pop the turret off over the weekend if you still need the ring diameter, but the model is stored away til Iget the time to finish paint it.