Thats pretty cool, i can only assume the fretmarkers are ebony ?? The body looks like centre seamed plywood ??. The maple board has some nice birdseye. You coud look for it in the catalogs as im no Aria pro Ii expert at all. There are a few people here who know these Arias though. Maybe they will chime in.
Badpenguin is absolutely correct about it being a PE-125. Without serial it will not be possible to say exactly which year it is from but it should be '76-77.
(And made in the Matsumoku factory in Japan)
And the holes in the headstock for tuners look like they fit tuners with a 10mm shaft so any in that size you like would be fine. If you want the vintage tuners with the 6mm shaft then you will need to also buy 10mm conversion bushings.