Once I got this done with all of the textures and stuff (and realising that I really really couldn't be a 3D artist), I started working on the actual engine. It's no where near complete (see the version number, still very alpha), but it's a start - available here: http://pastebin.com/Lrsi0wuS.
Anyway, I realised how much I like C, so that's good. Not quite as much as assembly programming, but close enough. There's a lot to do, so I need to get on with it.