Belated congrats!
I'm a little surprised that the P-90s struck you as having tone "one would often associate [with a] Gretsch with Filtertrons." Admittedly I only have one Gretsch with Filter'Trons, and they are of the more modern Blacktop variety, on my Pro Jet, which coincidentally I just played at band practice today. But I have a buttload of P-90 guitars (3 Specials [Gibson and Hamer USA], a WildKat, and a Casino), and I don't find that I would associate a Filter'Tron sound with that of a P-90. In fact, I wouldn't even associate a P-100 with a P-90, despite that being the former's entire
raison d'etre.
The only modern exception I've even heard of, to P-90's being pretty much their own thing, is the DeArmond 2K that was on some Guild-made FMIC DeArmond Aristocrats (although Fender simply called the guitars by M-series numbers, like M-72, etc., they were based on old Guild Aristocrats). The 2Ks, ironically enough, were in housings looking like Gretsch's
other iconic pickup, the Dynasonic, but reportedly were intentionally voiced to sound like P-90s. Although I've owned lots of those great DeArmond guitars, mine all had GoldTone pickups, which were bright PAFs, so I can't speak to the 2Ks' reported likeness to P-90s. An even more obscure possibility of a similar-to-P-90 pickup, is coincidentally on the
actual old Guild Aristocrats, the "Franz" pickup, which visually resembles a P-90, but old Guild's are way out of my price range (sadly), so I can't speak directly to that either. I honestly think I could, if blindfolded and played one of my P-90 guitars, and then the Filter'Tron'd Gretsch, could tell which was which a high percentage of the time. To me they're pretty distinguishable.
But I digress.
Obviously tone is highly subjective, so this isn't meant to be argumentative. One thing I have found interesting is this graphic, which I think was first published on some Gretsch site (it may still be there, for all I know), with which I'll end my TED Talk of a post:
Enjoy that Gretsch! I enjoy playing my two Jets.
