Now I just Googled Tube Research Labs and up pops a website that to me seems pretty suspect. The products referenced are mainly the older tube designs, none of the very popular solid state (Samson) or tube preamp (Dude) pieces. I really have to wonder who comprises this dedicated group of audiophiles and audio design engineers that are supposedly keeping Paul's legacy alive.
While it may or may not have any significance, it's perhaps noteworthy that Paul's original website was at tuberesearchlabs.com, while the present site is tuberesearchlab.com (without the "s" after "lab").
I did some checking and it appears that the original url expired and became inactive sometime in the last quarter of 2017, a bit less than two years after Paul passed away. And the present url was registered on 12-18-2017.
As I said, that **might** not be of any significance. But it just adds to the suspicions Clio09 cited.
To the OP, best of luck as you proceed, and thanks for calling this matter to our attention.
Regards,
-- Al