The various manuals which are on the SOHC/4 website have been moved to the new web site:
The
Tech Library contains some general manuals and articles including a whole list of Honda Service Bulletins.
The
CB500 section has a setup guide, parts guide, and service manual
For the
CB750, I have mostly just articles and wiring diagrams, but I'm working on getting service and owners manuals back online.
There is a service and an owners manual up for the
CB550.
And the
CB650 section has two owners manuals.
There is more to come as I get the time to get it online.