Since Mr. Stills is my Original Guitar Hero, I disappeared down the interwebs rathole for about a half-hour and could not come up with anything.
Yet.
Oh yes, welcome.
Yep, welcome aboard, Thomas!
I also have no recollection of ever seeing and F30 associated with Mr. Stills.
This is the only known Guild sighting I can recall, a "Duane Eddy DE-400" I think, because of chesterfield headstock, from Buffalo Springfield days:
Neil Young is also seen playing a DE-500 (?) (G-shield headstock) in a television performance of "For What It's Worth":
Can't recall for sure but seem to recall that was Stills' guitar as well.