If you don't want to fit the plastic replacements there are quite a few aftermarket stubby LED type indicators on eBay including some that look as if they will fix to rear plates or mudguards.
Presumably I'm going to need resistors for every light with the original electrics unless I do dig deep and get an m.unit, very tempting having spoken to Roo about his
There you go Dom, LED indicator flasher unit available on that same link that I posted earlier along with suitable LED bulbs for your bike..
https://www.classiccarleds.co.uk/products/12v-electronic-indicator-flasher-relay-classic-car-with-oe-click-x-l-p-2-3-pin
There you go, I'm showing my electrical ineptitude. Thanks matey!