The Square routing holes on the bottom of the pickup cavity are exactly the same. The Tokai and the no serial Grecos above are being routed by the same routing machine. A guitar doesn't get installed with Cor-Tek pots unless it's coming out of the Cort factory. The MIK Cort Grecos have distinctive routing like you say and they often have Cor-Tek pots.
Tokai pickup routing holes and diagonal wiring channel. It's amazing to think that Tokai Japan are currently using the same routers that they were using in the late 70s. I've traced the Tokai Square Holes back to late 70s Tokais up to the present and also to the late 70s Burnys that have a Tokai serial number and were made by Tokai and also to some of the Greco no serials that were made by Tokai and also to more recent 2007 Burnys that were made by Tokai and even to some (Martin) Sigmas that were made by Tokai in the 70s. Then there are other no serial Grecos that are very different and have no shielding paint and have the usual sloped nut and have fret edge binding and have a EGC-75 model stamped in the pickup cavity and square shaped pickup cavity routing holes and these are made by Tokai. There are Greco no serial Mint Collection guitars made by Cor-Tek (Cort) with shielding paint and brick shaped (no slope nuts) and most have Cor-Tek (Cort) pots.
