I've just replaced the two pieces of foam in my Westfalia upstairs bed. The original was 42 years old and a bit soft around the edges. Also a bit smelly. Did a quick search and found a company called GB Foam Direct. Turns out they are VW camper fans. The website is very easy to use. Lots of options and explanations for each. I ended up with “luxury firm sofa foam with added stockinette.” That was the best quality blue foam. They do a camper foam for a little less money. Just over £70 delivered Slept on it for a week and it’s brilliant. Highly recommended all round.