My 5056 has pretty high action on it, and these guitars are very bad candidates for neck resets, as the necks were glued with epoxy, not hide glue (which can be softened with heat). And actually, due to the neck attachment issues, I gravitate towards the 80's vintage, as they have had less time to have their neck angle change from string tension. To me, that's the first indicator that a guitar might be post 1980'ish. You'll see a lot of people claiming that they have, or are selling, 70's vintage Alvarez guitars, but have sound-hole truss-rod setup. I have another Alvarez from 1981-2, that adjusts in the sound-hole. As you can see from the response from SLM, the headstock truss-rod adjustment was on the earliest Alvarez guitars. FWIW: I have the same guitar, and it is around the same vintage as yours, with a 4 digit serial number and the headstock truss-rod adjustment.
