Pete Tascarella (and now with Pete Jr.) have been making their own blanks for almost the entire time the shop has been in business.
The only time they did not make their own blanks was when Pete Sr. first started putting cues together, using Szamboti and Spain blanks. But these were only a few cues.
As part of the equipment purchase, Pete received all of George's notes on building his cues as well as several cues and components in various stage of build (these weren't offered to other people trying to buy the shop stuff). This also included unturned Gus Szamboti glued/banded blanks.
Pete's brother in law was some kind of machinist who built the first Tascarella fixtures in order to make blanks way the hell back then before 99.99% of all cuemakers even started thinking about sniffing the wood glue. Photos of the Szamboti pre-turned blanks have been published. I think most people who have a desire and talent to build cues could figure out a process of blank-making (following the process is a whole different story) if armed with the notes and blanks in both turned and unturned stage.
There is absolutely zero reason to believe that Pete Tascarella wasn't building his own blanks early in the process.
He will build a cue with a John Davis blank, but with caveats as the current Davis blanks do not fit his cue specifications. The Tascarellas have been making their own full-splice blanks for quite some time as well. {edit: no idea how many are out there as they don't make many cues to begin with}
Freddie <~~~ wonders what jealous cuemakers continue to spread the falsehood