Looking somewhat Guildy to me. The back thing is aftermarket quite possibly. The 3pc neck construction and body look like a Guild Starfire iV early model, but the tuners are more Gibson like, single ring Klusons. The tailpiece looks like something you'd see on something really cheap like Stella, but the insert looks fairly legit.
Bridge style and knob don't look very Guild to me but just a reason to leaf through Hans's book and see and Guild bridges fall into two categories, Harp, and Guildsby. The harp on nearly forever, predating any double cutaway Starfire prototype, so that doesn't make any sense. Maybe more like the wrong parts.
Need to see the whole front, and front of headstock.
Leafed through the whole book, I don't see this shoddy of a bridge on anything Guild ever sold. Typical upstart underdog, their stuff is nicer than anyone else's.
Edit, Robert Lockwood Jr. SF-12 has a Stella like tailpiece on page 90.