I agree with Ax01. I wouldn't worry about the mold either...not that I'm encouraging to grow more, lol, but snakes are exposed to it in nature,
it's not a big deal. And I wouldn't have thrown away that cage (or whatever), just cleaned it.
I'm one of those that likes to give snakes plenty of space too, but keep in mind what your BP really likes: places to hide, tight "hides" to squeeze
into (they like to feel "back pressure"- it makes them feel safe from predators sneaking up on them), so if the new enclosure is lacking "furniture",
you should work on that. Not less than one 'hide' on the warm side & one on the cool side. And since you're using a glass tank, you might think
about covering (maybe insulating while you're at it?) the back & sides, both for the snake's sense of privacy AND to help keep the heat IN the cage
when colder seasons arrive.