Just to bring the thread to a close - I contacted Clasic Car LED and they supplied a replacement Flasher/Indicator relay (mounted in the relay/fuse box box in the engine bay of my car) and 4 x Amber LED 382 Bulbs. Simple plug and play and I also changed rear brake/tail to Red LED 380 bulbs to complete the set!
Great result Keith, especially discount if it's accepted

. Interesting that Duncan at Classic Car LED took you a different route to the solution by providing the LED friendly flasher relay and "plain" LED indicator bulbs. On later Plus 4 and Roadster the flasher relay is integrated with the esentially sealed BCU so you have to use their "CANBUS friendly" type with built in resistor.