My plan for this bike was to acquire all the parts, get her running and then start the restoration proper.
There was a lot more parts missing than first thought. That box of parts that came with the bike promised much but delivered little containing parts from bikes other than the 550K.
Anyway I now have the elusive seat bracket, fork ears etc. The replacement electrical loom was from an early 550K requiring a SSU which the bike doesn't have. For now, I've bypassed the SSU until I either get either an SSU or build my own equivalent. I've seen a few posts on her on how to do that. But for now the start motor whirrs, turn signals wink, horns hoot, light illuminate.
I hooked the bike up to the auxiliary gas tank and after a few tries, it started up. Strangely enough, it wouldn't start until after I did a compression test on one of the cylinders.
I only ran it briefly. It's running rough but idles okay.
Next step is to clean the carbs and then remove the engine and tackle the purple frame.