FYI - Kiesel's pickups are about 1mm less in length and 1mm less in width, than Nordstrand's P2 shaped covers. Kiesel's routes are also tight. I had to sand down the finish from the inner edges of the routes, to get Nordstrand BigRigs in a P2 shape, to fit into my Icon 5.
While it is a doable Project: if you know you want Nordstrands in a Kiesel and you have a Kiesel model which you already love, I would send the Nordstrands to Kiesel and have them build the bass with the Nordstrands. Small adjustments to the routing is something they will do, for pickups which you send in.
I do not know about the fitment for other brands, such as Aguilar or Bartolini. I am very intersted in the Aguilar Super Doubles, but my Icon is 17mm string spacing. Regular people can't get custom spacing from Aguilar.
But Nordstrand will build all sort of custom stuff. They were also FANTASTIC to communicate with and worked fast. 1 week to build the pickups and then get them in the mail. They even sent me a blank pickup cover for testing fitting, no charge.
If you don't want to mess with any routing and need a custom size pickup cover, I would ask them about the option of a what they call a "Raw" pickup. They basically use a harder bobbin material, to shape and build a custom pickup shape. It wouldn't look as "clean" in a solid color or metallic finish. But, it allows you to get Nordstrands in just about anything and does still look fine. However, I think it would great in a Raw tone finish, natural clear, Tung Oil, or Antique Ash Treatment. Someday when I order another Kiesel, a raw tone or AAT is highly likely, for me. So, I might actually get "Raw" pickups anyway, for that look.
Raw Pickups
Here's a new, crappy cellphone shot of my Alnico III BigRigs. Maybe someday I will actually do a sound demo...
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