[Reldma]

I also have a 1999 and have done some wood replacement on mine and here is what I found. The wood around the windows and doors is so they had something of strength to screw them into. I have replaced the wood on the roof of the shell and around the doors. The bottom of the top shell is 1 inch aluminum and no wood on the front section. The rear top shell has both 1" X 1 1/2" wood and 1" aluminum tubing. Some will say there is no aluminum in the 99's but according to what I have found and the factory they started using aluminum back then.
When we had our TM in the factory for some adjustments I asked about replacing the walls with the wood and wallpaper on them and Ed told me that he wouldn't do it. That was enough for me not to try it.
Also Ed at the factory told me that the strength in holding the walls together is the glue and a good glue for me to use was Gorilla glue and I have used it with great success so far.
Good luck and they really are kind of easy to work on.
Ray