The foam situation I found quite annoying. We had a double memory foam mattress for many years - it was fine to sit on, very comfortable to sleep on too and only cost about £100. With hindsight I wish I'd chopped it up for the camper.
Same, we made an initial mistake with just 50mm of hard foam, went back to the upholstery shop and they suggested the thick memory foam as an addition Our cushions are not particularly constrained by the Devon bed.
I was initially going to do that except I need a 4" thick mattress and at 4" they're all mattress "Toppers" I think. Is that different stuff? Who knows. As everyone says - I need to go along and sit on some. I will return with my findings.
The Ikea mattress toppers are memory foam - we did consider keeping the thin cushions and using a cheaper Ikea mattress topper but it is bulky to store in a Bay.
Rather than get a bit thats all things to all men. Get a firmer piece to sit on. Upholster will recommend the right foam as they do seating not beds. Then get 2 softer bits for the seat back and bed sticking your feet on the firmer stuff.
The foam used by westys is spot on, not sure where it is still available. Very comfy and keeps it shape. Try and find someone who is stripping theirs as the rear mattress is excellent.
Mine is a Continental, but you have probably slept in more than me. Foam in mine is still extremely comfortable and nearly fifty years old and should be OK I think.
If Carlsburg did foam , they would probably call it The Wife , obviously the best foam in the world…..Probably! If your lucky that is Sent from my iPhone using Tapatalk
I made the mistake by using semi firm 4” foam on my rusty Lee bed and recently maybe because of the heat it’s seems way to firm almost like rock. So at the moment we resort to adding 50mm memory foam and 50mm soft topper , crazy I know , I even made ventilation holes at the rear to allow air to escape when the foam is compressed. Sent from my iPhone using Tapatalk