Have you tried the 3D ContentCentral yet? Maybe try contacting Hurricane Burners directly and see if they supply a model?
ETA: Boerderij Kabouterhas some really nice sketchup models, and it looks like the banjo is modeled in his HERMS plan. I know it won't dump right into SW, but at least its a start...
Looks like I'll have to come up with an interesting mounting bracket.
I did look on 3d content central. No luck. Not sure if the mfg would really want to give up the iges, i think it's made in China, and easy to knock off.