Here's my take on T-tops: They are Gibson pickups from just after the Golden Age...
So they are basically the same, except for a couple of things:
1. By about the middle '60s, Gibson had changed their bobbin winding equipment to give
uniform and predictable product. Before that, bobbins were wound by humans, who each
had a mind and a heart, and a limit to their attention span. Golden Age PAF Gibson p'ups were
wound till the bobbins "were full." So there was variance among the hum buckers... Modern
OCD guitar collector types value the variance, and treat it like treasure, just like stamp collectors will pay big
money for some stamps that have flaws that were corrected later.
The fact that the PAF pickups had variance was looked at by factory engineers as a flaw, something out
of control. Factory engineers are all about control.
Just like the sound engineers of the same time period regarded distortion as "amp failure."
Factory engineers like to turn out consistent, predictable product. So they changed to winding
machines they could set to 5000 turns, and the pickups they produced are called T-tops.
Factory engineers could never have imagined that 65 years later, musicians would obsess about
the variations in the early PAF pickups and pay large money for real ones (or that there would be a healthy
market for fake PAF pickups). But musicians like to seize any advantage, in a competitive business.
So they will pay extra for the supposed advantages of PAF pickups, without ever measuring how many
turns of wire they have on their bobbins.
2. What are T-tops then? They are Gibson pickups wound in the late sixties maybe and early 70s.
They were wound to uniform specs. So... no variations. Or at least less variations.
They get their name from the factory imprint of a T on the top of the bobbin. T stands for top.
Just a way of getting more uniformity in the product, and a guide to the worker, so he or she can work faster.
They are said to be slightly different in tone from PAF or later "Patent Number" pickups.
Maybe Gibson sourced their winding wire from a different maker. Maybe Gibson changed the gauge of the wire.
In those days, the people who made these things could never have imagined the level of obsession shown by
musicians and collectors... about tiny details of construction. Gibson changed the size of the magnet too in those days.
And musicians became all fussy, and complained that they couldn't sound like Clapton (who was gawd) and played a '59.
So they kept stealing Clapton's Les Pauls. *grins
It wasn't long before DiMarzio and Seymour Duncan began marketing 'replacement" pickups for '70s guitarists
so they could sound more like gawd. Amps didn't have master volume controls then, so "hotter" pickups were
all the rage. Guys ripped the T-tops out of their Gibsons, and installed the flavor of the week. Hundreds or
even thousands of T-tops probably were just thrown away. But they sound great.
It's so silly IMHO. Now people treasure the old pickups and pay extra for them. Gibson began wax potting the T Tops
in the mid seventies, and those wax potted pickups are called 'Tarbacks." Designed by Bill Lawrence, they also have
different magnets and are hotter. Those were also panned at the time, even though they sound great. Guys just like
to rip their pickups out, chasing the tone in their heads. That has not changed.