These were the brainchild of David Pelham, who sadly passed away in 2013. Bryan Purves took over the project after David’s passing and he continues to supply these worldwide. He tells me that he can’t get enough of them! The price is 53 GBP and can be ordered from Bryan via his website http://www.bryanpurves.co.uk/contact-bryan/4578606936 If phoning, he is available to answer on Tues/Wed/Thurs. Please note that these will not fit the 5-speed gearbox.