Original P.A.F

[Mincer]

I thought the Seths were wound to match the patent, not how things were done in the 50's, so the coils were 'identical' and more controlled on the wire spec (min/nom/max)?

That was my understanding. I'd love to know if that is correct.

[AlexR]

The magnet metal mix, the impurities in the other metal bits, the wire diameter itself as well as the coating thickness all were differences to what you get today unless you make a very expensive special order.
Then you have the machine, which wound differently depending on what location on the machine the bobbin was mounted. The turn count is not hugely different (despite urban legends that say differently). Much of the K differences are attributed to wire gauge and winding tension. And of course unless you know the very settings used it is hard to get to the same place as what the machine was doing in the 50's.
Not sure if SD brings in parts specifically for the Seth and Ant, but the winding patterns seem quite regular compared with the very lopsided/irregular vintage bobbins. And also they are nominally a balanced turn count.

What this means is that SD wants to try and make a more consistent pickup that will suit more guitars. PAF clones and the real thing are quite temperamental - they need just the right instrument or they don't sound right.