The bus sure looks 100% better now, nice work. It looks like fido is happy too.
Re the floors, all I can say is you never know until you peek. I cut away some of my vinyl to inspect the floor and oh man, glad I did as I ended up looking at nasty old wood. So I pulled it all out, coated the floors, and added insulation and then osb board and I'm pretty happy. Either way good luck.