There's a bunch of reasons you see all these variations.
First of all, many Alembics are custom-built to the requests of the buyer. They'll have different preferences on things like logos, inlay, etc.
Second, you see evolution of the instrument's construction over the 30+ years that Alembic has been making them. For many years, there was only the headstock logo but the name Alembic probably didn't appear anywhere but on the circuit boards inside! They were so distinctive that they were immediately identifiable by appearance (or completely un-indentifiable by rarity). I think the script logo was added to the headstock in the mid-80's, and it seems like it's gone away again lately.
Most instruments have a brass bird tailpiece, but some of the early ones have that ebony piece underneath. I'd be willing to bet that this was probably one way of fixing an error in the thickness of the piece without recutting a new one. Getting the dimensions of bridge and tailpiece right on a through body instrument (where you can't shim the neck to adjust the angle) is always a challenge. The ebony spacer made a re-appearance a couple of years ago on some special edition (was it the Stanley Brown Basses?).
There's also a lot of variation in things like the pickup appearance over the years. Originally, they were flat, unmarked tops and many were in caramel brown and other colors. Then it was unmarked black, followed by black with Alembic embossed into the surface. Then it was Alembic marked in gold foil.
Each one is different, like a snowflake!
David Fung
