by Dark Frame
This a previously 'tuned' EQ6 mount lacking one DEC axis bearing. You know, the tiny one. Can't miss it. 68mm diameter, 15mm thick. With a 40mm hole. Useful.
No wonder the new owner noted a wobbly DEC Axis which wouldn't calibrate in PHD, with his 10" scope and counterweights on it.
Always check what was done if someone has claimed to have rebuilt their mount, and you're looking to buy it. Not all builds are equal.
Get a demo if you can.