Thanks to efforts of various members, we have a kiln!
It is apparently a Gallenkamp Muffle Furnace exact type: unknown.
Please be careful hacking this as there may be asbestos inside of it. The asbestos should be internal (i.e. only a risk if you open up the back etc) but please be careful and wear a mask (asbestos safe) until confirmed one way or another.
Not to be touched or used until asbestos status has been determined. Jonty is checking this out.