The HF1300 actually turns up fairly regularly on UK Ebay but be aware there are 4, 8, 16, and even a 32 ohm version (used in dual parallel arrays), so you should measure yours or examine any markings, then try to find a similar one. Since they are small and light, you might be able to get one shipped or convince a UK shipper to ship. Occasionally, they show up on US or Canadian Ebay as well.