I messaged Seymour Customer Support after purchasing a Brent Mason Tele and it doesn't have the same pickup cover - they were very polite and replied with the following:
"After doing little more digging, I found out that we did supply the pickups to Fender for the Brent Mason Signature Telecaster. As with any manufacturer, we make the pickups to the technical and cosmetic specifications provided by the manufacturer. Fender had asked for us to make the Burgundy covers for the STK-S2 stacks.
As it turns out, when Fender asked us to recreate these pickups for Brent's signature model, we did have a box of covers from the 80s with the stamped "S" logo. We used those covers for the pickups until they were gone.
Because we needed to change materials for the covers, and because we have not had the molding for the "S" stamped covers for many, many years now, Fender approved that we use a non-logo burgundy cover in the latest build of those pickups, made exclusively for the Brent Mason Telecaster.
On their website, Fender still has photos of the Brent Mason signature model with the stamped logo. Many online dealers have updated their online photos with the non-logo middle pickup."