So, it looks like starter can not rotate the crankshaft even a little bit?
I would try rotating a crankshaft with a wrench, a little bit, only to get it off the potentially damaged tooth or two, then to re-check.
The starter solonoid copper contacts are toasted. You can replace them yourself(depending on brand) or get a new starter unit. A 21 year old starter had probably 46.000 starts in its lifetime…no wonder it failed.
If the starter motor is running, its copper solenoid contacts are not the problem. This sounds more like a problem with the starter’s gear not meshing with the teeth on the flywheel. I’d try the greendrag0n’s idea and see what happens.
Greendragon might be right. The teeth are not be connecting. Will i see it after i remove the starter? Or are the teeth/flywheel somewhere else?
When you remove the starter you’ll see a little bit of the flywheel - actually of the ring of teeth that go all around the outer circumference of the flywheel. Maybe some of those teeth are broken, and if the starter’s gear happens to be resting on a section of broken flywheel teeth, you can get the starter to run but it has nothing to engage with.
There could also be a problem with the gear on the end of the starter motor - with its teeth, or with the mechanism that lets it drive in one direction, to spin the flywheel, but freewheel in the other when the engine starts.