I did this mod. last year. I went to a good hardware store and bought
a concrete float, used for smoothing out concrete. It is a very hefty
handle with a metal plate attached to it with screws, the plate is
countersunk so that the screws don't contact the concrete. I pulled
the padding away, managed to bend the metal plate into the curve of
the dolly, screwed it all back together, and used 3M HS-90 spray
adhesive to glue the felt back on. I wanted the plate so the screws
wouldn't pull through the fiberglass. Very simple, cheap, looks really
good.