Started to read this thread and TBH I thought you were going down the restoration road. However you seem to have gone in a different direction altogether, some I like and some I'm not keen on.
Anyway a few words of advice from a long term CB500-4 owner who has restored a few of these now, they benefit a LOT from using taper rollers in the headstock, you mention bearings so I naturally assume you've fitted ball bearings, taper rollers are much better as they stiffen up the front end a treat and are much smoother in operation.
The rear indicators are using the rear mudguard bolts holes, they may not fit when you install the rear guard.
I'd seriously reconsider the fitment of the stock air box, it might not look great but without some sort of filtration you'll struggle getting the mixture right and the lack of filtration will ruin the engine over time, maybe K&Ns would be better than no filtration.
I had an engine powder coated, mine was done in silver for the crankcase halves, black for head and barrels with the edges of the fins polished like 80s Yamahas, skullcap was silver with breather cover black, all bolt on bits like oil filter housing and oil pan were black. All the outside casings were chromed along with the carb tops and carb bowls, even the choke mechanism was chromed. Nice job on the carbs BTW, impressive.
I like you had my exhaust clamps rechromed, however in practice it doesn't really work, as your chromer said they do discolour and rust at the bottom of the fins, next time I have them done I'm going to grind the fins off and end up with plain rings which should polish up well and accept chrome better.
Just as a matter of interest was the rea drum cracked? I've yet to see one that didn't show some sign of cracking.
Another suggestion, try a CB900F master cylinder, better fluid pumpage and has the mirror mount if you need it.