Looks like ill have no option the extenders bought 10yrs ago German Manfr excellent piece of kit.They and leads Magnecor no issues in 12 yrs , had heat plate bracket coming off Supercharger break chaffed 2 leads .
You can buy all the bits to make your own leads, makes it easy to do spares should you ever need to. The seller Mr Retro Leads on eBay is pretty good for the bits.