Thank you belatedly for the birthday wishes, Don.
Work has been nuts but it's finally starting to slow down and I've made some progress. I'll be posting pictures in the next day or two.
Essentially, on the 500, I decided to redo the wiring inside the battery box and clean it up. I'm much more pleased with the overall layout & cleanliness of the set up now. This week, I'll be finishing up the wiring and cranking the engine. I still have to work out the proper spacers in the wheels as the ones I'm using now aren't lining everything up properly and there is still a bit of a wobble in the wheels. Once I do all of that, I'm hoping to get it out on the road for some road testing this weekend or next week at the latest.
On the 550, I purchased another 550 engine yesterday. I had to drive an hour west of Atlanta out in the country but I bought a complete 550 engine plus carbs and headers for $150. Based on the engine's serial number, it's a 1974 K0 CB550 engine but I have no idea how many miles are on it, as it had been being used as an engine on a go-kart.
Once I finish the 500, I'm going to get the 550 engine running and do a compression and leakdown test on it to see if it needs a rebuild or not. At the very least, it needs cleaning up and repainting and the carbs will need to be cleaned. And I won't be using the headers on this bike, as I plan to buy the entire exhaust setup for this bike which is going to be a keeper.