Thanks for doing this. I expected wafer resistors, but we have naked bobbins.
Using four resistors in each location allows Fluke to correct second and third order tempo effects. These resistors have to hold steady to 8 digits to deliver the 0.1 ppm resolution.
The two resistors at the top are part of the bridge used to balance the resistor values.
This thread does give me an idea. The 0 - 0.1 setting has no adjustment pot, and is the reference for the whole instrument. If that string is too far off, it forces many modifications to the other strings. Therefore, we could simply switch it with another string, and make balancing easier.