Yeah, it seems like it. The only thing I wonder about is all that plywood in there. I wouldn't think that it's the ideal material to maintain good gas mileage, but it does give it a warm look.
the plywood paneling in the roof section should be remarkably light. 1/4" panels don't weigh much and would bend easily. Also - keep in mind - when you get a bus like this, you're loosing all of the steel seating - so I imagine trading the seats for the wooden furniture might be a wash - or even a net loss of weight - but that's just my speculation.
Yea I was wondering about that, I'd like to see pictures of it from before the renovation. I'm guessing the seats and flooring that were originally in there must have weighed a lot so the overall weight probably hasn't gone up too much... hard to say really.