Well, it spent nearly a month in transit over the Christmas break from the US to NZ but my second hand L200 has arrived!
It suffered a tiny bit of damage on the journey, the neon bulb and shutter had broken away from the bar used to rotate it in front of the slit. Fixed with a bit of araldite.
The previous owner has done a really nice job of the construction, far better than I would have been able to
I believe it's a 4th generation model, with an Edmunds slit assembly and a Vixen flip mirror with a beam splitter. I will probably order the reflective slit upgrade once my bank balance recovers a bit.
The previous owner made an experimental 2400 line grating assembly, it will be interesting to see if this works in practice.
Very rough first light images attached, just slapped my DSLR on, no real focus or slit width tuning but ... rainbows!!!