The mattresses are a special size for the RV. When we had the 2008 2350 I was going to replace the mattress because it got very uncomfortable. There were a couple of places in Florida that I looked into. One was in Fort Lauderdale. This was the company I was looking into to http://www.comfortcustombedding.com/
. Barry sold the RV before we had it replaced so my problem was solved.
If you do a search online you'll find other companies in FL.
For us the polyurethane took care of 99% of the wood splinters so that is another way to prevent the problem.
If you call PC they could also advise you on where to get another mattress or they may even sell you one. If they are going to an RV show in your area you might even ask them to bring it down with them.
A word of warning on turning the mattress over. When we got our 2551 we asked Carol if they could be turned and she said no. The twin ones are made with two types of foam - a more firmer foam on the bottom and then a sleeping foam on top. She told us the label should always be on the top side. I do not know if this is true for all mattress sizes and I also know that it was not true for model year 2008. I do not know when they changed.