One surprise that I had was when I removed the lower front sill, behind it was another whole other layer of rotted sill that was bolted to the frame. So I had to dig both layers out, and squeeze new layers in. It was a lot of work. But... It feels good to know that there is no hidden rot though, and once she is back on the road, I will not have to worry about instability or leaks.
I also had to replace some rotted flooring by the door. This required me to remove a section of rotted plywood and replace the rotted crossmember. Then put in a new layer of plywood. I had some plywood of the right size that was painted blue, so thats why the patch is that colour.
The latest framing that I just finished, is around the door. It is pretty challenging to remove rotted wood off of 1/8 thick paneling, especially when there is a layer of glue involved. But I got it done, and you can see the fresh header and framing around the door.
In the first photo you can see how rotted the wood is around the door.
In the last photo, you can see all the new framing, including a strong new door header.
Yes... I know it looks like a lot of work. It is a lot of work, but it's a hobby, and very enjoyable as long as you are not in a hurry. And I'm not in a hurry.