I bought a multibridle recently and I’m pretty happy with it but since I live in the US it didn’t come with the strap for the crossover bitless option. I couldn’t find any replacement parts for sale from Horseware or on eBay; does anyone possibly have one they’re looking to sell? I have the standard horse bridle in brown.
I don’t know of anyone who sells or owns one, but something you might consider is having a strap made. It wouldn’t be terribly difficult to measure, and some of the stores who sell custom bitless and trail bridles might be willing to make one for you. Two specifically come to mind, but others could probably name several more. This gentleman on ebay (http://www.ebay.com/itm/Bitless-Bridles-By-Skips-Bitless-Bridle-Natural-Leather-Entry-Level-/282061084902?var=&hash=item41ac2698e6:m:mlGNqw8Zuoq4ItSWXh2meCQ ) is very good about returning emails, and Two Horse Tack (http://twohorsetack.com/c-5-other-items-you-need.aspx) could probably also make you one (if you wanted a beta version). I’ve ordered from both and was pleased with the jobs they did.
I had one made using, I think, an old plain rein.