Today I happen to go to savers and saw this there. It looks like its in good condition other than missing half the bumper and its a little dirty. I have not tried it out yet.
Your Royal looks like a model 9100. It would use the 7 amp (non-drop-in) motor. Maybe the fan blades and/or bearings need check up? It can't sound as insane as those 8/9/10-amp models from 1995 and thereafter.