OK, so I sorted out all my re-wiring and was able to replace my stock honda huge instrument cluster with a much smaller and streamlined single mini-speedometer with four instrument lights combined in it.
I used a CB400A wiring clymer manual image that I found online to sort out which wires connect where. I also cleared up quite a few wire clusters that no longer needed to leave the headlight wire storage area and made space for the new connections.
VERY satisfying! Can’t wait to fire her up tomorrow and hopefully the speedo/odometer work properly and track accurately. The indicator lights I could test (blinkers, hi-beam, as well as instrument backlight) work. Will see if my neutral light works tomorrow too (and hopefully will not see the “oil pressure” light come on ever )