Bill-the first thing I would do is take that truck to a Semi truck wash like Blue Beacon or Truck-o-mat. They will have some acid that they spray on aluminum wheels and tanks. It will take all the corrosion and garbage off, and turn the wheels and nice bright white. After that then I would start the polishing. At least this way you would not be trying to polish through the years of grime. **NOTE** after you get them polished do not go back and get the acid bath, this will pull all the polish off and turn the wheels from shiney to a brite white again, BTDT!! Good luck. I hope your arms are in shape!!
Michael