I have a '96 Eclipse. You might wanna re-check the serial number of the one you are looking at, I don't believe Hamer was making the Eclipse in '83. IIRC they started in '94. The Eclipse is one of my favorites Hamers. I love the body shape with the "beer belly bevel" and "forearm relief". Lightweight for a solid mahog guitar. Its a very comfortable guitar for me to play. Some critics think the body shape is odd. In fact, wasn't there a recent thread here speculating on the perceived "lack of respect" for the Eclipse? I like the Wilkinson wraparound bridge on my Eclipse. It works out perfectly, which was not the case with the Wiliky wraparound on my Artist. I suggest you carefully checkout the intonation on the one you are considering.
As for shortcomings, some people complain about the pups. Duncan mini-hums, someone please check me on this, its an SM-3 in the neck and an SM-2 in the bridge? Many people do not like the sound, describing it as harsh. Many switch to Gibson mini-hums. I stuck with the Duncans and was able to dial out what I did not like with the guitar tone pot and the tone stack on my amp. I highly recommend twisting a few pots before you sink money into new pups.
Going price for an ordinary stock Hamer USA Eclipse with OHSC seems to be around $450 to $550.