Class C without a house battery bank???

I called the seller back and was very persistent on it having house batteries. I saw online where it had "dual 6 volt deep cycle auxiliary batteries. He was getting somewhat ill with me on my insisting that it had more than one battery. (Chassis battery) In his defense, he's 78 years old, original owner and bought it new. I told him about the auxiliary starting switch on the dash. He said that he had used it once! I said "how do you think it started then since your house battery was dead?" That got him to thinking....he finally started searching more and found 2-6 volt batteries!! He sent me a picture of them. They were probably 8 years old, still working! Within the next hour, he had gone and bought new replacements. He thanked me and said he was thankful that I had been so persistent. He is such a nice gentleman. I intend on going to see it, hopefully this week. Thanks everyone!