Mk2 steering rack part number problem

Hi my motor on steering has gone according to vcds permanent red light heavy steering expected with 262000 miles I suppose. Any way rang up tps and skoda they both gave me part number 1k2 423 055 k as latest one this supersedes letter c to j. However after ringing breakers and looking through ebay everyone seems to have ones out of octavias with part number 1k2 423 051 bd etc all ending 051 with letter if I give this code to tps I doesn't come up on system, all the ones on ebay etc end 051 anyone can help thanks mines 1.9 tdi 2004 54 plate mk2