About the only thing I have seen with a bigger trunk was the Mercury Monterey. Had a 64 Montclair Breezeway and rebuilt it from the tires up. Looked just like this. That is what I do for entertainment in my retirement. I take Classics and rebuild them frame up and flip them. You could absolutely put a double mattress or six bales of hay in these... :)
I love those old boats... They were designed to ride nice even on washboard dirt roads. :)