My 1923 Singer has never failed. Many tents, Flys and awnings. Took it in for tuning and was told it's a tailor machine. That said I had to make several boat cushions. Anyone needs it come on down and we'll get it out for you.

Do love insulation, none in my 82 Glasnose though because I am lazy, but maybe one day. The absolute best would be to hire a Urethane guy to come and spray foam the walls, then shave them back where needed. The next best is urethane foam board, closed cell if you can find it, open cell is ok. Just a bit behind that is poly styrene bead board. Some folks like fiberglass but not good in an RV it will pack due to bouncing on the road. Either way a lot of effort.

Wow, that carpet looks great!

Those curtains look stout too. I also bought an HD Singer thinking it was for heavy duty and discovered it wasn't quite. Honey dew is much more fitting!