It is one of the nicest chippers out there. Very solid, chips well.
Mind you not all are created equal.
Does the one you are looking at have a 'crotch cruncher'? (It is a hydrolic ram that forces the upper feed wheel down) those make all the difference.
I would avoid the auto feed option on the early models.
One option offered was (or still is) an extension for the discharge chute well worth the $ if you are chipping into a partially covered truck bed, It really directs the flow of chips exactly.
You said it was a 50 horse diesel. The one I used was a Duetz air cooled engine. Is this a Perkins? I have never been fond of the Perkins. They are long running engines but use 50-60 year old technology.
Bandit 90 means it will chip up to 9" material. It is a little chipper that works very hard. So check for sloppy bearings, worn bed knife, clutch wear etc etc
Good luck
Frans