Re: Custom Shop Broadcaster vs. Production model??
Point #1) Don't get too hung up on the printed numbers.
If you can, check out the book "The Blackguard" by Nacho Baños. ISBN:84-609-6633-X. 9_788460_966333. This illustrates numerous individual Fender instruments made between 1950 and 1954. There is no single exact specification for a Broadcaster pickup pair.
Point #2) Be guided by your ears rather than your theories and expectations.
I used to be prejudiced in favour of vulcanised fibreboard bobbin plates, Alnico magnets and, on Tele Rhythm/neck position pickups, a particular metal formulation for the cover.
All of my pet theories were blown out of the water when I first encountered G&L ASAT Classic MFD single coil pickups. Upon refreshing a dry solder joint on an output cable, I observed that the pickups featured underslung ceramic bar magnets. (Quelle horreur!) Through a good valve amplifier, they sound and respond like great, old Telecaster pickups.
More recently, I have tried the larger MFD pickups. These also do much of what I would like a Telecaster to do only with a hint of Gibson P90 muscle thrown in.