HP PSC 1410, Black cardridge #21 and #56?

HP cartridges are wayyyy expensive in Finland as well as the rest of the world it seems. Today I found a JetTec alternative which looked right for my printer, the alternative is #56 and my printer needs #21. I didn't pay too much for it so am not really bothered but I wanna know.. if I were to peel off the copper sticker from my original cartridge and stick it on the new one, would it work? The cartridge fits perfectly but the printer won't accept it. Anyone got any ideas on how to make it work? Thanks for your time.