Dumore Grinder

Just got a Dumore 1/2 hp "master" model grinder from ebay advertised as "good running condition"...well I guess that means you want to run away from it, since the spindle make a hell of a howl. Anyway the motor seems okay, so maybe its worth fixing. It came with two spindles, both of which have bad bearings. I opened the older one of the two spindles, a model "T", and pressed out the bearings. It seems the bearings are retained on the shaft at each end with a press fit steel collar with a small tapered brass insert, one of the collars cracked during removal. Dumore does not have parts for the older spindles. Finally my questions: 1.) has anyone had one of these apart? 2.) Are the collar/brass rings a standard part? 3.) Anyone have a spindle they want to sell? 4.) The newer spindle, (8/85) has a different construction - can the bearings in this be replaced more easily? 5.) Why does the latter spindle say "do not oil" ?, are the latter ones sealed bearings?