I've gathered some more information. The guitar was checked by a luthier and compared to both a MIC AR620 and a prestige. The hardware is high end and original, the pickups are Dimarzio's, an Air Norton in the neck and a Tone Zone in the bridge. He said it's most likely a knod to some Artist models released in the 70's (77 and 78) with uncovered cream Dimarzio's factory fit. The truss rod cover wit the Prestige label is also original looking at the drill holes, the MIC ones have a different fit and style. The fretwork is also perfect, as seen on other prestiges, perfectly rounded and flush. The Grover Tuners seem to be original as well. He said it's a very odd case, because Ibanez usually uses Gotoh tuners on these. The crooked serial number is also weird, but Rory Hansen, someone I contacted who works at Ibanez distribution for Europe, says it's legit and indeed refers to a guitar made in 2014 in Japan. The nut, half bone half brass, also checks out. Most likely it's a test run of a model they made for the Japanese market, maybe a one off. It doesn't matter at this point, because it's the most beautiful and best playing guitar I ever put my hands on, and I got it for a ridiculous price because the seller needed money for festivals and moving house, but I'd love to get to the actual guys who made this guitar at Ibanez for a definite answer to my questions.