I'm just comparing the internals of the guitars. I'm not making any claims that I'm 100% right, I'm just following pointers to where they lead. Some of the no serial Grecos have Cor-Tek pots and must be from Cort but the guitar above is not from Cort. It looks Japanese but has no serial so who would be likely to make it. From the pickup and control cavity routing and wiring I can compare them to other pickup and control cavity routing and wiring. I have a sort of routing and wiring database of known guitar makers and I then compare them.
The guitar above has routing and wiring internals that exactly match Tokais. I's not from Fujigen for instance because I've never seen a Fujigen guitar with those square routing holes at the bottom of the pickup cavity and Fujigens control routing is very different as well. If you get a G serial OBG LP and a K Orville LP and a ink stamped no letter Orville LP and compare the routing and wiring channels and tenons then the G serial OBG and K Orville match exactly and the ink stamped no letter Orville doesn't match with the G serial OBG and K Orville.
Why would the G serial OBG and K Orville match. If the K Orvilles were coming from Korea like the Cort made Grecos did than there would have to be routing and wiring channels and tenon differences like the Cort made Grecos have when compared to the Fujigen made Grecos. I did all this Orville comparing after Jim Donahue from Hoshino told me that he saw Orvilles only at Terada and Fujigen and he did not see them at any Korean factories. So the Orville comparing just backs up what he said.
So all the OBG and Orville LPs only have 2 different styles of routing and wiring and tenons. Hmmmmm, 2 different styles, 2 different makers, Terada and Fujigen from Jim Donahue. Because Terada didn't serialize their Orvilles and Fujigen did serialize their Orvilles it threw most people into a Korean no serial thing like the Korean Samicks were known for.