Looks like you have your fun laid out for the next couple months. As long as you have the know how, time, and $, it'll be a good project for you. Try to keep anything that needs to be replaced intact to use as a template. Good job on the tent structure. That'll make the work almost enjoyable. I did a similar structure but used clear tarp on the inside and outside of my walls and ceiling. I had to replace my trucks head gaskets in the middle of one of out coldest and most persistant winters. Had a heater out there with me too and got the tent up to 70 degrees while it was in the 20's outside. Glad that's behind me now. Hopefully soon you'll be able to look back at this and think glad that's done too.
J