From what I can see of them, they look a lot like Jerzy pickups, which are also split-coils. Did your friend model them after those specifically?
Regarding construction, resistance and inductance? No, these are a project he started a good 5 years ago from scratch. More than 80 or 90 prototypes until he achieved something he actually likes.
The pickup covers do resemble Jerzy's...
Here's some better pictures of the bass I'm playing on the first clip:
Mine will have "Jacarandá da Bahia" (Brazilian rosewood) as top and fretboard, since he lives right in Bahia and can still get some good Dalbergia Nigra from local sources. It's going to look like this one, but not single-cut.
