I commute on an older Miyata 10 speed, rack and fenders, I think it's a higher end model than yours but hi-ten. It's delightful. I think it's about 37 yrs old now, looks shiny new. Plush ride. As long as you aren't expecting your Sport to cruise at 17-20mph I think you'll be happy. I kept the original stem shifters as well as the drive train & steel wheels, learned to love it as a package.
If you are serious about touring in it, you might do some hill climbing and a century as a test...see if you can live with the weight, wheels and gearing.