I was joking around. I don't know about high gain circuits, but my Reeves and Hiwatt both came with JJ's stock, and there was no wet cardboard to be found. Both amps sounded amazing from the moment I got them.
That said, now they're loaded with NOS Telefunken and Mullard ECC83's, with NOS Mullard EL34's in the Hiwatt, and I still have JJ E34L's in the Reeves.