Don't know how much I can add...except that those do look like two fine knives.
I've had probably 20 or so of Wendell's knives, and have I think 10 right now, and I've enjoyed them all. I'm not sure if there is a set way that he dates his work, as I too have owned knives dated on the blade...dated only on the small certificate, and I have one from 1982 signed and dated on the inner liner. Also, one of my favorites came from Wendell, in a plain box, with no certificate, undated, and marked only with the Queen Big Q...

It does seem like most of the newer knives are coming in a box (several different colors) marked with a snorting bull and Fightin Bull-USA underneath. The box also says established in 1998. But, I'm sure Wendell was doing knives long before that, so maybe that was the official beginning of the Fightin Bull line. Most everything in the last 3-4 years HAS come with a certificate. Many of the knives have not had a shield, but those that do have shields, have been the Fightin Bull like shown above.
For the most part, I like the materials Wendell uses for covers. I have/have had Pearl, Smoked Pearl, Sea Cow, Whale Baleen, several different Jigged Bone models, Sambar Stag, Interior Mammoth Ivory, and Bark Mammoth Ivory. And I may have forgotten 1 or 2...
So, don't know if that was of any interest...but it didn't improve my typing much.
Bill