Rik,
Very, very nice! What an unusual trailer and I love the kids bunk. You've incorporated some really nice items in your trailer.
I wanted to take a moment to talk about the pvc or the like, roofing material.
Though I wouldn't change mine and I'm very happy with it, it's not for everyone. You mention how up-close, every small detail of covered nails, etc show up.
Well, this happened with ours under the pvc material. To look perfect, you would have to probably have a VERY smooth surface. Ours really shows any inperfections underneath and there are more than a few!
Certain areas are smooth as butter...doors, hatch.
Aluminum or paint would probably be more forgiving.
I LOVE mine though. Looks weren't as important to me as the insulating qualities, low maintenance and cost. We were looking more at functionality than anything else...and will keep it in the family since we built it.
Good luck on whatever you choose. I'm looking forward to seeing how Chip's trailer turns out too!
Bev