did you buy that set in switzerland?
they are rare.........your only bet is to keep a running search on various ebay sites (not just one, because of the languages)
so ebay germany "BWA alfa Felgen Emblem"
ebay usa "BWA alfa wheel centres"
and ebay italy "BWA alfa Borchia"
these were (are still?) cheap! (the emblems alone must be 1-200 Euros for a perfect set, lots of people in USA looking for them)
VENDO 4 cerchi BWA con borchia Alfa Romeo Genova (151254) Annunci gratuiti Auto d'epoca, storiche e moderne