I added the certificates for my images above in the post where I said I would do an edit within 23 hours. The certs are recent, from last month, and I do not know if either has a "cert history."
Now I trust everyone who has replied here so far knows this, but I wanted to explain to those who are still learning, the E-grill ridging runs up and down (or if you prefer, north and south) while the Z-grill has the ridges running left and right (or if you prefer, east and west). Now if you did not see that difference in orientation go back and look. For further help see the linked article.
Siegel Auction Gallery wrote and has posted a good explanation of grills, especially the Z-grill, here: https://siegelauctions.com/enc/pdf/1868Z.pdf
And lastly thanks for your illustration jleb1979; more good illustrations are a better teaching tool. If I still hand my color 85A photos, I would have posted them to show the double grill. They were used for the front page article (Linn's or Stamp Collector) I wrote about the stamp prior to when the Jerry Buss collection was being sold in 1986 by Superior Stamp and Coin Co. of Beverly Hills, CA.
If one is in the market and can handle the quality, or lack thereof, both can be found currently listed on eBay
. They are not mine nor am I trying to advertise for the seller. As I stated in my OP, they are shown here due to the quality of the pictured grills.