Just thought I would add some pictures I took while constructing the Snitch diorama. The basic frame was made from plasticard and square section plastic rod, and the sewer and access hole were constructed from pieces of ABS pipe I found in a local DIY store. They were all joined together with plastic solvent - you need the sort that works with ABS though. The hardest thing was joining the two tubes together - that required a little careful accuracy in the cutting and gluing, and even then there were some small gaps to fill.
I wanted the outside box itself to be as smooth as possible - so I filled and sanded all the joins, the aim was to make it look like a solid plinth.
I clad the inside of the pipes with brick textured plasticard - and cut out some of the bricks to make the surface look a little uneven and worn. The rungs were made from brass wire, and the platform he's standing on from plasticard and copper wire mesh.
I filled the whole box with plaster of paris - I wanted it to have some weight, and stability. The tricky bit with that was to ensure there were no holes in the construction...
I'll post some pictures of the street level, and the painted scene soon