It looks great.
Unfortunately, those incandescent bulb type UV lights aren't really. They try to be by blocking all but the highest frequencies from escaping. But, since incandescent bulbs don't produce much in that wavelength, it really just sort of glows purple, while turning the captured light into heat.
They don't look as steamy, but you can get compact fluorescent UV bulbs. And those do not give off much heat at all, while giving off quite a bit of UV light.
(I used to be a prop-builder for a haunted house)
Thanks for that info... I did see the fluorescent bulbs in Maplin... It's not the UV that's really important more the overall look... I have a Squirrel cage bulb I want to try in it but I have to put in an "appropriate" dimming device... It will look like an arc of brass studs with a handle to increase/decrease the power but will cunningly hide the fact that it's a dimmer switch under the box lid... or, maybe, a long throw fader... decisions, decisions....