Yeah its not rocket science, its just resistors in series with each led on a common pc. Ill count them and tell you the values if you really want so you can replicate it with some veroboard, might save 15 quid in the long term

The point about the board is that you just screw it in place, crimp it on and voila its done and its lasted for a year of single vibes, and my acerbis rear guard tends to wobble too, so a easy life it has not had. Its quite well arranged, with all the resistors being glued by their bodies to the pcb in addition to the legs being soldered. Cant comment on the bulb packaged units though.
Ive already done the rubber mounting route, and I had a c90 bulb holder in there too with extra earth wires running back to the battery, but it still tended to pop when I ran offroad, and as my lights are perm wired on to eliminate another switch from the system, it was a common experience to find the filaments in the bottom of the bulb.
The other reason for going led, was that I could run one of goffy's 6v halogen bulbs up front with the extra power, as the amount of power available on a sp is pitiful with normal filament bulbs. The leds are also much brighter than the oem bulbs ever were, and Ive got a headlight that actually is worth having for the first time in 15+ years of ownership. Still on my first halogen bulb too...