I LOVE the 7.62 TT round, for both shooting and collecting, and I absolutely HATE the CZ52. They are not rare or even particularly scarce, and they are horrible shooters. They have uncomfortable grips and triggers, and as mentioned above, they are know for fragility with moderate to hot ammo. Why keep it? Both traders you mentioned are worth more than the CZ.
Dump the mule.
Dump the mule.