I just purchased what I believe to be a Clark c500-120 but some things are not adding up. It has a fuel tank and a fuel gauge, yet it is LPG powered. Furthermore, from what I can find, the Clark c500-120 was a diesel powered fork yet this has a 6 cylinder Continental engine. I can only find that engine in yard models made by Clark yet this is a cushion tire warehouse model. To add additional mystery, the data plate is not a clark data plate, but one from a company called Powr Lift (not a typo). I'm in the DFW metroplex area and apparently this company is as well, if they still exist. Is it possible that this company modified the forklift with the Continental LPG engine? Thanks for any thoughts.