He mostly used an early "Laminated Steel Indestructible By Gunpowder"

And is the picture you included of that steel
Indestructible By Gunpowder?
W.W. was promoting his "Greener's Solid Weldless-Twist Barrel" and his dad's "Silver (Laminated) Steel"
Yes, but my problem is knowing the timing. I would assume that his weldless-twist wasn't something he was doing early on in his career. Don't know about his silver steel barrels. Most of the references I've seen to those are to Silver Steel Damascus, with twisted patterns.
When W.W started his own business he tried to concentrate on breechloaders rather than the muzzleloaders his father insisted on. He apparently never made a large number of muzzleloaders. I have a W.W. Greener muzzleloader made in 1871-73, earlier rather than later in that range. The pattern I asked about is from that gun. I'm trying to unscramble all the conflicting historical threads to see if I can find out just what I have.
Thanks for the link. I have the 9th edition and it is very close to the 3rd you showed.
Bob