Jesus Hilly Pushy bugger aren'yt ya.... Actually the only way I think you will get that done is to walk in with the heads and ask on the spot.... And they will give you a hit load of excuses about why they can't do it therre and then......
How much are you looking at taking off anyway?
RHD see "spanner" the owner.
Burdekin motorycles are good as well. Dave wont do the heads himself but the guy who does them for him builds performance engines and drag racing engines. Dont think you will get same day turnaround though.
Cheers
Robbo