There's really not a lot of info out there about this particular model of Aria, or more precisely this Arai Diamond hollowbody which was an early Matsumoku made semi acoustic.
In 1965 Arai changed the name of their hollowbody guitars and basses to Arai Diamond while solidbody versions were still named Arai due to the trademark of ARIA being owned by Kawai. One of the first hollow bodies offered in mid/late 1965 was the sharp double cutaway 1302T model at 25.00 JY. Quickly after in early '66 two slightly cheaper round double cutaway models were introduced. The 1202T at 23.500 JY and the 1850T at 17.500 JY. These were the same body and neck with the 1202 having block inlays and upgraded hardware and electronics with a master volume and tone for each pickup.
The body design of these is VERY Harmony/Silvertone H75 which had been introduced several years previous, with the bolt on neck set right out on that body extension and 3 piece F holes. The 1202T would eventually get matching pearloid or tortoishell headstock veneer to match switch surround and scratchplate just like the Harmony.
Hollow bodies started selling really well in the mid 60's and all the big Japanese brands offered many different versions in many different price ranges. By '67 Matsumoku was offering a huge range of Harmony, Gibson, Rickenbacker and Hofner style hollowbodies including full body Gibson style single Florentine and round cutaway archtops.
The 1850T is a great hollowbody for the money and in my opinion plays and sounds better than the equivalent Harmony models thanks in part to being manufactured by the GREAT Matsumoku factory and also due to those great trapezoid single coil pickups. These pickups were fitted to many solid and hollow Aria models from around '66 and I have been a fan since I first heard them many years ago. They're a high output single coil that sounds like a P-90 with slightly less mids and more sparkly top end and, they work great in both the solids and hollows.
The bodies are well constructed from nice laminate with double binding and nicely finished internal structures. The thin bolt on neck is, like most arias, a joy to play and well finished with a nice bound rosewood fretboard. The headstock on these earlier ones was based on the classic Gibson headstock while later versions had the big, laminated face headstocks.
The hardware is all good quality and I'm a huge fan of these Aria plastic roller bridges. Not only do they work well but I like the way they sound.
This early version has the trapeze tail vibrato which I've written about before. These are a unique and brilliant set up which keeps the tone of the classic trapeze tailpiece with the option of a vibrato.
This body shape lasted well into the 70's under several different model names and proved to be a good selling hollowbody under many different brands around the world and would eventually morph into the slightly more traditional 5102T which was also made under several different brands including Guyatone.
While the more common 1202T probably gets more love, these more simple versions are very cool and I'm a fan of the 2 knobs and dot neck which takes some of the bling away from the very ornate more expensive version.