Hi there
No, it's worth almost nothing at all and is practically useless, but I'll take it off your hands for 50GBP.
;-)
Actually - it's a bit of a holy grail thing for several of us on this board who would dearly love to MIDI-up our theremins, but really can't afford (or justify to better halves) the cost of 400GBP to purchase a new one.
More details are available at www.theremin.co.uk (http://www.rothman8.freeserve.co.uk/tmin.html#mcv1a)
So, in short, yes it is worth something, and I'm sure others here at Theremin World would offer money for it (probably more than I could hope to offer pre-Christmas). Failing that, you could try sticking it on eBay.
Good luck with finding somebody to appreciate it and make beautiful music with it!