No aftermarket assemblies that I'm aware of. Salvage yards only. Find somebody on Ebay parting out a 150G and send them a message if they don't have the assembly listed. Sometimes, they have parts they haven't listed yet. Of course, it's a crap shoot, as theirs might be as bad as yours.
The rheostat, knobs, and switch are all "standard" parts and can be substituted, if you can find some that fit.
