Interesting... I saw one sold recently for $750 at a tool dealer. The one I saw locally has an asking price of $200...

In my opinion, not worth it even if it was free. (Unless you can
cannibalize the motor and trash the rest ....)

.... has a semi-transparent orange blade guard on it and appears to be in good shape. I assume it came out of a school. ...

I would not be surprised. The one I had did come from a school.

.... Sounds like the machine would work on end grain?

Yikes! No way - that's asking for trouble. Why joint the end of a
board when you have a chop saw, a sliding miter saw, or a radial arm
saw? Or even crosscut it on a table saw if it's not ungainly.