Good luck with your restoration.
My current project is a 1977 Honda XL350. Like your CD200, parts (engine or body) new DO NOT EXIST:)
I think the best way to go about is get full information about your machine and know where/how RENEWING old parts eg. chrome, galvanise, powder coating, paint etc.
Its always great to have a factory/service manual to help you - and guide your EXPERIANCED mechanic. They could be found on the internet.
Also consider getting a DONOR engine/bike - this helps alot!
Your bikes seems surprisingly complete-capitalise on that.
Hope this helps......