I made some OBC LED replacements, but they didn't have enough diffusion to fully illuminate the buttons.
There's some Ebay guys out of Hong Kong selling LEDs and the resistor needed for 12v operation.
you just need a donor bulb for the end caps, and some inventor's perf PC board for the chasis.
you don't need to encapsulate the LEDs like these showen, so you can just mount them on the PC board and trim to fit the old bulb and end cap dimensions
I've been pondering a third brake light for the touring, but don't know if it will freak out the CCM.