I remember these, hmmm. I think the older ones were based on a novel oscillator that had a neon in it which was pretty in the dark with the covers off!
All the best,
Norm
PS: A bit harsh on the old Wasp, they actually sound reasonable if you bypass the internal speaker. I had one for a bit with the additional seperate 'real' keyboard (Caterpillar!) and sequencer. For recording sessions I would borrow another three from friends and drive all four polyphonically from the keyboard. A working man's Obie 4 voice...