Not the double buckle ones. I bought mine...now on Adrian's Roadster...from Simmonds who I think was the only person making them. He's now closed up most of his business and is concentrating on his steering wheels as far as I know.
It might be worth contacting him though in case he still has any around.
Otherwise I'd recommend contacting Malvern Saddle Co Ltd who I believe do some of the accessories for MMC and may be able to help.
