Going this weekend to check out a used hearthstone stove, guy does not no the model. Looks ok in the one provided picture. Is there anything I should look for to be wrong? Can I tell if the cat is still good? If it needed one are they readily availble and reasonably priced? Guy is looking for 600 with any left over wood that he has if it is in good shape seems like it would beat buying a brand new one. Thanks in advance for any help