Construction definitely follows the P90 format overall. I don't think the insulating foil is part of the original Mosrite design. Here's some info on bobbin dimensions from mosriteforum.com. Given that the original style magnets with snap-to-length corregation are pretty much impossible to find, you're never going to have it "exact", but there are a few builders making Mosrite style pickups with modern parts that sound great.
Good luck! Mel
66 Ventures bass bobbin:
This may differ a little as the bobbin is crudely handmade. 10,000 turns of AWG43 will result in around 10kOhms – so I'd put 11,000–12,000 turns on the bridge PU and a little less on the neck PU.