$5-10K, but it would be real hard to call that good working order. You'll put 40 hours or repairs into the first 10 hours working. Then again, prices lately are insane, so it's really hard to guess what something will sell for.
I have absolutely no idea what machinery goes for in your neighborhood. That said, if the hourmeter is correct, and still functioning during your test drive, then the machine is worth some sort of premium. Duh.... Can you still get packing for cylinders? Can you still buy shuttle parts, if the machine has one? (sorry, vintage Case guy here) In THIS neighborhood, that machine is $10-12k, assuming decent support from the local dealer. I would try to pin those parts folks down before I made a serious offer.
I'm still looking for that hour meter.
Its a subjective term.