My touring days are over, but if I were looking to do some serious touring again, the first two bicycles that come to mind are a Trek 720, and a Miyata 1000. All others are simply pretenders to the crown of "best touring bike ever". I put many thousands of miles on my '83 Trek 720, fully loaded front and back. Your Miyata is very similar, and some would give the 1000 the top prize as best ever.
It's not about being retro. It's that the Miyata 1000 was built for the serious bicycle tourist, at a time when that was a big thing. Even if most people never actually did loaded touring over long distances, they could if they wanted to. There's not much demand for those kinds of bikes any more. If you wanted to tour today and had to buy a new bike of the same quality, I think you'd have to buy a Rivendell Atlantis. A Surly LHT would probably do the job too, and I'm sure there are a few others.
Enjoy your Miyata 1000. Give it all the love and attention it deserves as far as restoring it. Once you've reached the minimum number of posts, we'd love to see pictures of it.