that looks super nice. It looks like you're spending a lot of your "budget" on those railings. If I was you I would try to use alpha or masked textures instead.
https://www.quaddicted.com/files/wads/blood_transparent.zip
you will have to put a { as the first character in the texture name in order for the pink bit to be transparent. And transparency isn't supported in some engines like Dark Places, I hear you can write a shader but I have no clue how that works. You could also make things like cobwebs to get a creepy mansion vibe going on.