It looks quite like a SB-R80 to me, but there are a few things which concern me apart from the missing serial number. The top of the headstock is not like any Aria shape I've seen from the 80s - compare it to the black headstock I linked. Plus, the input jack should be recessed. On my SB-R80 the control panel cover was brass and the truss rod cover was plastic with the model number on it. Yours looks the other way around. They're not Aria stamped tuners either. I've never seen a fake SB but I've never seen one like this either.
Hi Guys, I've just bought myself a nice Aria Pro II from a local guitar shop. Some info on various Aria Pro II (Korea) guitars, their serial numbers.
The through neck doesn't look centred, there's more neck-through on the bass side and the bridge is off-centre too. Perhaps some of the Aria Gurus here might be able to confirm? I think you've been sold a fake, you ought to contact the seller asap. I reckon Jovino has it - it's not a faker.
There's a bit in the APII catalogues that says something along the lines of 'specifications may change without notice'. With Aria, that's not a threat, it's a promise No serial number + the headstock design tweak = Not Made in Japan. Production shifted to Taiwan & Korea between 1985/87 & the Matsumoku factory ceased production altogether in 1987, & got wiped out in the Kobe Earthquake in 1995. Odds are the S/N was on a little black & gold paper sticker that's long since fallen off.