cabinhill-
Here is a selection of 30A transfer switches available from bestconverter.com. Give Randy a call ((888) 828-1893)) and ask him which one he would recommend. Some may fit better in the spot where your old switch is installed.
Also, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their RV there, so they don't have to type it into each message. Instructions for adding a signature are
here.