Jon, we really need to know the engine...is it a 4 or 6 cyl?  
Does it have grilles in the nose?  are they mesh looking or do they have horizontal bars?  Or is there just one grill on the front that goes all the way across?
Above the grilles is there an oliver medallion or just a thin strip of metal with raised bars?  If there is a medallion is it shaped liket the oliver shield or is it oval shaped and just says Oliver.
We need a little more info