Mr Keppel points out some stunning kits offered by the German company, Sun Watch (translated) – one of which is the above Magic Lantern kit!  Constructed from stiff cardboard, and arriving with lenses, electric lights and a series of slides, all that is left to do is assemble and glue the contraption together.  It looks marvellous for a cardboard kit, and the company also does microscopes, telescopes, Stirling engines(!), sextants and sundials – it’s all I can do not to convince myself I need one of each!  I’ve not found a specifically UK or US supplier for these yet, but this company seems to ship internationally (it is battery powered, not mains).
Of course, if you were feeling slightly more adventurous (or less wealthy) you could attempt to make your own by following the instructional video on a slide projector recently posted on Make (thank you, Lucky).  I’m sure with the correct Steampunk styled casing it’d be a delight to behold.