Whas just wonderin what you guys recon is the go here. Obviously not bloody chip board again but I was thinking of marine ply but it might weigh a bit much. Mainly just to replace the stuffed chip board sections not a complete refit.

We used plywood for our interior and pine for the benchtop. We put stain on the pine and a clear varnish on cupboards and bench top, trimmed it with a decorative wooden trim and it looks Mickey Mouse. We live at Boondall Brisbane if you want to take a look. I know you said you were not doing a refit, but if you or anyone else wants some good ideas for interiors check out http://www.calypsocampers.com  for great ideas.

if your painting it, then i would go for mdf, cheap easy to use and once painted looks great

Been thinking of doing the same thing. I could not believe how heavy the original chipboard is! To save weight I'm going to use thin plywood as much as possible. MDF would be OK but I want to keep the "wood grain" look and the simplest way to do it is to put a clear coat on plywood.

mdf is easy to work with and lighter than the same thickness of ply. also bends easier for kick panels etc.

A bit of advice when using MDF....
Our local hardware shops here in Canberra WILL NOT cut down MDF boards. It poses an OH&S issue apparently. If you plan on using MDF then may I suggest 1. do it outside in well ventilated area 2. wear a face mask (just to cover nose/mouth). Having said this the mother inlaw(outlaw) uses MDF for craft applications quite often, so dont let me put you off!

yeh the glue the holds ti together contains a form of fromaldehide (SP?) i think, nt good, but adust mask and no probs

ive used a mix, MDF for the cabinet doors and benchtops, ply for the shelves and cubboard sides. ply is stronger and will survive water better, but is heavier. i will be using ply for my door trims.