Folks have inquired on www.PracticalMachinist.com whether there are alternatives to the Kluber greases specified by Deckel for their milling machine spindles.  I found the following cached page on Google that hints at some possible alternatives.  The original page seems to have evaporated.  Obviously it is up to the user to figure out whether any of these greases will really serve as substitutes.  The dN numbers are the bearing bore diameter in millimeters multiplied by the speed in RPM.