Congrats on the new ( to you ) RV.
First is that most people have separate insurance and roadside assistance.
Motorhome insurance can be purchased from most major auto insurance companies and some RV speciality companies. I personally have progressive but had State Farm before.
Roadside assistance can be purchased from several also, the two biggest would be CoachNet and GoodSam ERS.
Breakdown and repair coverage is a different animal though. Several companies offer Extended warrenty and repair, but some would not accept your motorhome due to age. Also if you did decide to purchase one of these, be really sure you read all the fine print as most are really restrictive and you must follow their instrucrions to the letter.