Hi Mica!
All measurement on this pickup is same like on Alembic pickup(BxWxT)and they have same curvature,on the top no radius it is flat no see any differences, and a hole for screw is at same distance.
As I can measure on Om-meter one pickup have a two spool of wire and each spool have 1.8 KOhm, they are put together in parallel mode and output from pickup is only .8 KOhm so I am asking my self is this some old series of alembic pickup, because no any kind of Alembic copies with a same dimensions and curvatures on net, or maybe it's pickup is a result cooperation with Mr.Arai?