Full review is coming! In the interim, note the copper-plated steel (I assume it is steel and will verify) plate on the bottom just like the originals - this really will change the tone and is a key to a classic tele sound. Also I'm going to get more info on the wire/wrapping used as the leads and the pickup itself have a very waxy feel to them - I included a pic of the side of the pickup to show this unique wrapping.
From the manufacturer:
Vintage-correct reproduction of Broadcaster® pickup. Recommended for traditional country, country pop, chicken pickin', rockabilly, blues, and blues-rock.
The 1948 pre-Telecaster® pickup had an exceptional twangy, "nasal" sound with tremendous sustain. Leo Fender called it the Broadcaster®. The STL-1b duplicates this sought-after vintage sound with larger-diameter (.197") pole pieces in a flat pole piece orientation. Compared to the Vintage '54, this pickup has slightly more output and more snarl in the mids. Comes with waxed cloth hookup cable.
Available in lead (bridge) position only. The STR-1 is the correct match in the rhythm (neck) position.
For all well-balanced instruments. Works equally well with maple and rosewood fingerboards.
Duke Robillard, Seth Yacovone, Jodee Frawlee / Starr Faithfull, Al Anderson / Wailers & Lauren Hill, Adam Gaynor / Matchbox 20, Doug Pettibone / Lucinda Williams
Best videos/sound clips:
Check out this clip from Six-string Samurai Gear Reviews of the Seymour Duncan Vintage Broadcaster pickup set. Focusing on the STL-1b pickup, skip to 0:35 to hear its impressive rhythm and lead tones. On one hand, you can get a twangy funk-style lead with a lot of percussive attack and midrange snarl. For lead sounds, you can get a really nice crisp high-end with plenty of presence and bite for a vintage Fender tone. Blend the STL-1b with a complimentary neck pickup like the STR-1 and you will get a nice balance of compressed punch with snappy twang for a timeless sound.
The player is Ed Lim and he is playing a Fender Telecaster through a Mesa Boogie Mark Five amp.