I looked at the information you found, that .130" less shoulder contact is huge when you consider that the #84 spindle has next to nothing. My thought is that nearly all trailer axles have about the same bearing to spindle clearance as I have found.
The idea just mentioned about using an adhesive would work, I even have plenty of the right type on hand. The problem is that the spindle would become very difficult to service and might require heat to disassemble. With PA state inspections pulling the hubs yearly, that is not an option.