can i get a copy of previous visa from british embassy?

[marty]

Hi there
im wondering if i could get a copy of my old working holiday visa which i had in my previous passport? im gonna apply for fiancee visa and i need the reference number of previous visa. so im worried about it coz passport office kept my old visa when i got a new one coz the old one was damaged.And now i end up having no proofs and no stamps from uk. i know i got national insurance number etc etc. but they could think i over stayed which i didnt do . pls i need some advice.
im gonna call british high commission where they gave me my visa in 2004 but just want some more sdvice.
thanx.
marty