When you get a moment, adding your geo-location to your profile will help, especially when searching for spare parts.
EDIT
One option is get in touch with these guys and ask if you can buy the spring on its own. DK m/c's or 2 wheel spares. Ebay item 315498537423. Fowlers list the bike as having the same part as the Turbo.
Otherwise, again Fowlers, it is listed as replaced with 92081-1265. It does not look the same but it may fit & work.