Mellotronists

today i acquired what seems to be 4 panels of EMSA modular.
it's a bit rough, has been canibalized for some parts, and
has no power supply, but looks to be a very cool project
for me to restore this over the next couple months.

trouble is, i can find little or no information on it.
the person that gave it to me thought it was something
made by "southwest technologies", but i have never heard
of them, and searched turn up nothing.

the only ID on these things are the letters "JRS" on every
panel, and a couple panel IDs: PWG-2 and M-VCA-5

so i need to figure out what the power supply requirements
are, and possibly identify some of the components inside.

i thought i knew some good analogue synth reference sources,
but none of them are turning up anything, except one site
had a list of reviews/articles that included the PWG-2,
but it was just the review title - no actual review.

anyone have a clue as to where i may turn?
i know everett hafner passed away a few years ago, otherwise
i would have called him [he ran EMSA and i dealt with him
for some parts to my synthi AKS years ago... a great man]


thanks in advance, and sorry to veer off-topic.
off-list replies are fine if you prefer.

jeff