SergeModular

Does anybody know how many variations the Serge faceplates have had, and
when they were done?

There was the original Calarts batch (with a rubber-stamped horse?).
Then they went to the first production modules with the adhesive backed
paper & mylar. When did the first aluminum panels come in? I saw a
couple panels made of dark blue plastic - with early Serge filters,
phase shifters etc behind. Was this a one-off or a short production
run?

Thanks

John P.