I have 2x custom made 7 string single coils available. Both have Alnico 5 poles for the wound strings, Alnico 2 for the plain treble strings. They're overwound, intended for neck or middle positions when combined with a bridge position humbucker.
Pickup 1 is wound with 8500 turns of 42 gauge wire, so it's the closest of them to a standard S pickup.
Pickup 2 has 8500 turns of heavy build 43 gauge wire, which tightens it up a little and pushes the mids, making it work better with gain IMO. I've been having a lot of fun with the same spec in a HS arrangement.
AUD$100 each, including standard airmail to most places. Fancy post services will incur additional cost.
Construction-wise, they use shorter magnets than usual, which creates a slightly shorter coil with a little less string pull. These are not intended to fit covers, the flatwork is full size. Will fit Universe middle position. With the exception of height, dimensions are identical to SD's published 7 string drawings, minus the V. Flatwork is black FR4 (PCB material sans copper), so much sturdier than traditional vulcanised fiber.
Not the best final photo here, it was night -
Pickups before tape and potting -
Will either stand up to a Blaze bridge?