Well finally I've decided to buy the IRD swiss cups and install them on a economic cartridge, VP-BC73 that jrstewart3 has checked its fit with. Anyway the fix has gone pricy because there are no IRD retailers in Spain and I got to bought it from Nederlans (54€! total with shipping costs) Another reason to have chosen IRD is that you don't need to buy an specific tool for its installation as with the Phil Wood ones.
As I getting near to my 10th post I will be able to finally show you some pics when I get there with the installation. Thanks a lot to everybody