Airfix Colossal Mantis

Run for the hills! I'm not sure when I bought this kit, but it has been started. Probably around 40 years ago. However, I've recently got hold of the resin base set for these monster kits, so now seems like a good time to take another look at this.
I note that the caboose, cars and figures all seem to be different scales. Not a great start. All are poorly executed too. Judging by the length of the caboose, I'd say we're close to N gauge railway here. Maybe I can find some better alternatives, although I doubt model railway layouts have much call for a panicking mob! I'm also tempted to cut the window apertures out of the building, glaze them, and stick the VoodooFX fire lighting effect inside. One or two spotlights shining up at the beasie should turn this into a decent night scene. Maybe a lamp post or two would work too. The thickness of the base means I'll have to raise up the original cardboard backdrop a bit. Any other suggestions?