An 85 miyata 610 was a solid touring bike.
Personally, a lot would change for any of the bikes to make it a better fit for what I want/need.
- swap the 27" wheels for some modern quality 700c wheels with 36 spokes. A modern rim profile is inherently stronger/stiffer(whatever you want to call it) than 35 year old single wall box rims.
this will give you room for a larger tire too.
- modern aero brake levers and new brake pads for better/easier
- wider handlebar with modern compact bend for comfort and versatility.
- bar end shifters or STI shifters. Microshift or Shimano, whichever has best price for the drivetrain setup I want(3x9 for example) that gives good gesr range.
That list may seem like a lot, but it really isnt. Any bike you get will need to be completely overhauled due to age to ensure its greased and adjusted properly, so slapping on a handful of different t components while you are at it isnt too much extra work.