C500 is not a complete model number - but rather a a design style that covered trucks from 3000 lb up to 15,000 lb & maybe larger lifts starting in 1969. You need to supply a complete model number (eg C500-50 (5k cushion or C500 Y -080 8k pneumatic tire) and serial number - ususaly found on a a metal (aluminum) plate pop riveted on the forklift close to the operator seat - some times on the front side cowling (aka dasboard). If this plate is missing the serial number will be stamped frame in the following format XXXX-XXXX-XXXXX - the actual number of digits may vary & there maybe letters in the first & third numbers. On older machines these numbers may have been painted over several times - start scrapping). The complete s/n is the most important bit of information.