Jaguar vs. MFD (Original) vs. Lace Pickup Patents

Spoiler alert - Vast similarity Avoiding a thread hijack, could not help noticing these are my three favorite pickups:

• Jaguar: (1962) Alnico polepieces with steel 'claw' for bottom/side EMF shielding, which directs magnetic field tight around the bobbin
• MFD: ('81 / '82 ?) Ceramic magnet with metal 'retainer' for bottom/side EMF shielding, which directs magnetic field tight around the bobbin
• Lace: (1985) Micro-coil with very thin wire surrounded by rubber magnets which themselves form a 'retainer' for bottom/side EMF shielding, that directs the magnetic field tight around the bobbin

EDIT: I know the final MFDs didn't implement the additional shielding; wonder why?

Spoiler alert - Vast similarity Avoiding a thread hijack, could not help noticing these are my three favorite pickups:

• Jaguar: (1962) Alnico polepieces with steel 'claw' for bottom/side EMF shielding, which directs magnetic field tight around the bobbin
• MFD: ('81 / '82 ?) Ceramic magnet with metal 'retainer' for bottom/side EMF shielding, which directs magnetic field tight around the bobbin
• Lace: (1985) Micro-coil with very thin wire surrounded by rubber magnets which themselves form a 'retainer' for bottom/side EMF shielding, that directs the magnetic field tight around the bobbin

EDIT: I know the final MFDs didn't implement the additional shielding; wonder why?

The only info we have on the MFD single coil pickups used in the S-500 is this post from Gabe in the early days of the G&LDP:
S-500 single coil size pickups on early 80's model.
This quote from that post says the U-shaped keeper was abandoned on the production version of these pickups.

The narrow square shouldered MFD pickups you are interested in were Leo Fender's very first single
coil MFD design and you can see them referenced in his 1979 patent. The earliest incarnation had a
neat "U" shaped keeper plate designed for altering the magnetic field and shielding the coils. These were
found on a host of prototypical/experimental instruments starting as early as 1980 but did not get used in
a production model until 1982 with the introduction of the S-500 model. The production version of this
pickup abandoned the U-shaped keeper.

I also found this reference on Greg Gagliano's S-500 (1982) page:

G&L collector and researcher, Gabe Dellevigne, notes that the S-500's bridge pickup is wider than the middle or neck pickups. Also, the hot (+) pickup wires for the neck and middle pickups are shielded (co-ax).

Perhaps Gabe and Greg know the reason for the change to the production version without the U-shaped keeper.
I can only guess that perhaps the feature was deemed not worth the extra production cost.

Hope this helps.

Shame; it actually works well on the Jaguar as far as cutting out EMF noise (the metal plates contribute as well shielding-wise.) Another shame, co-axial shielding is something I observe more in cheap bottom-tier Chinese electronics than actual US or respectable import instruments, somehow; Duncans don't do it (not anything other than two-wire humbuckers anyway,) but some embarrassingly inexpensive no-names I've run across do, even for single coils.