I hope your mechanic inspected the radius arm bushings, top and bottom (IIRC, that series still used the twin I front axle). The bushings at the axle ends and frame mounting point tend to take a beating after 20-some years, and could explain a lot of the play or loose feel.
The other significant factor in that system is the kingpins. They tend to get very sticky with just a little moisture incursion. A good hint is that if the upper and lower kingpin bushings do not accept grease very easily, there is likely rust in the bushings, binding up the steering. This tends to create a tight front end which requires more steering input to control, and that can very often be mistaken for "loose" steering or "wandering" down the road. Another sign of that is that despite proper caster adjustment, the wheels do not return to relative center by themselves after negotiating a turn. You might want to drive it yourself and pay close attention to the symptoms
It's a good platform, and so long as the body is in decent condition and it runs well otherwise, it's probably worth investing a few bucks to repair rather than replace. I can't imaging shopping for a lift van and finding any kind of bargain.