Thanks, Duck.  Yeah.  If I replace the rear wheels with casters, I will definitely step up the size a back to 3" casters.  I don't really want to make the rear wheels larger than 10" but it might allow me to change the front casters back to the original 3" size.  

--Nathan, TX. Hire the lazy man. He may not do as much work but that's because he will find a better way.