I just checked out 109 and 1008 (they started with 1000 in that series, so techincally 1008 could be thought of as GT40P #9) and 1009 in Ronnie Spain's book. At this point, unless #9 is not the right number, I would have serious doubts about this man's claim. I also checked the owner's list in the back and there is no Stunson listed with any first name. Again, I would be highly skeptical.
There is an outside chance that it could be listed under a business name. Do you know the name of the restoration business? (He could be holding it for the proper owner as well; awaiting restoration, but this is a very long shot and, again, assumes that #9 is probably not the actual chassis number or even sequence number.)
Lynn