As you all know, non-neo cabs are heavy. My back doesn't particularly like this. I decided to use my welding skills and whip up a solution to the problem:
The most expensive part of the project (well, besides the $2000 welder) were the casters, which came in at about $16 with shipping from McMaster-Carr. There's probably $5 worth of 1" steel angle iron and some Rustoleum hammer-tone black paint for probably $25 total invested.
I could've fit everything flush so that the 4 pieces of angle laid flat against the cab, but because the cab has the big plastic corner protectors I made the side pieces hold the weight and the front/rear pieces are just for stability. All in all, a success. A sheet of 1/4" plywood would make a nice, stable bottom but I really don't see the need for it.