I also watched the antiques road show, but this one was in England, and they showed a train car with a Howitzer on the back that had a hand crank that worked and everything, it was in total mint condition, the hand crank turned the gun around, and the appraiser said if it was a different subject it would have brought a whole lot more money.
The trouble was with it being a war item, and not to much demand, go figure, but you should of seen the frowns when he give the appraisal, cause they even mentioned that it must of been never used to be in such great shape.
I still think it brought close to a thousand pounds cause of it being in mint condition