Make sure the focusing patch can go to infinity to ensure it hasn't been knocked off center.
Check that the meter is within tolerance.
Check the leatherette
Check the seals
Check the shutter speed
Check everything you would on another camera
Oh and something that everyone always neglects...check the flash mount. Make sure it fires!
Zeiss should still be offering servicing. Discontinuation didn't happen that long ago. I wouldn't be worried if I were you!