Had a nice morning ride a few weeks ago on my early 90's Kuwahara MTB turned into a monstercross. Last summer I repainted the frame (Tange steel) and replaced pretty much all the parts except the headset.

It's a great bike for leisurely gravel rides or long distance touring. It's super comfortable and stable. It's not much of a mountain bike in modern standards, but as a bomb proof touring bike I think it's getting close to a Surly Long Haul Trucker.