So here's my take on your situation. I understand that carbs can be complicated and confusing for folks who are first diving in. But they're honestly not bad to deal with, and your PD carbs are not horrible by any means. Missing parts surely are obnoxious to deal with, but luckily most (if not all) are available on the usual sites.
So far as manuals go, the original factory service manual definitely is best. I think there's a digital version in the forums. And the best tool you can have in your arsenal is patience.
One real problem is that the CB650 needs carbs that came with the CB650. Spacing will not work with other carbs. You have the option of finding a carb repair shop and having them do the work but it will cost north of $400 which is genuinely insane.
So sit down, watch some videos about folks rebuilding these carbs, look through the parts diagrams, and reset yourself before giving in. Don't take shortcuts. You'll thank yourself when you fire it up and it runs well enough to ride.
