After consulting Hans' book, I would say it definitely is the X-660.Maybe the rare X-660 Hans wrote about?
Yes, going from memory, I thought it was Friends of the Archtop Guitar. I had to go to my activity log when I couldn’t find it there myself.Ahh ok Vintage Guitar Collectors, not Archtops, no wonder I couldn't find that photo.
Now I wonder what the difference between the X-1770 and the X-660 are... @hansmoustAfter consulting Hans' book, I would say it definitely is the X-660.
Master tone control on the cutaway, not volume! The similar vintage ES350 had two pickups, two volumes, and also a master tone on the cutaway.Those should be pre 1955 ES-5, with individual volume controls plus master volume on the treble bout.