Looking good Elvis!
Here's what I have on the widescreen PADDs... Their first appearance is in Season 3's "The Bonding" where one was used as a video photo album of sorts. Then the style disappears until Season 4, where it appears in at least 7 episodes, and is then never seen again (at least not that I noted when re-watching TNG last year). At least two were made with one display screen persisting for all of season 4 and the other changing as needed.
First appearance in 3x05, The Bonding
The PADD has a black/blank screen since video is meant to be composited into the shot:
New display screen graphic added for season 4. Later screencaps show it more clearly but it is a diagram of the Enterprise D in side profile
4x08 Future Imperfect
The second new display screen with art of a solar system. The other widescreen PADD with the Enterprise graphic is on the coffee table in the background:
4x09 Final Mission
Not sure which of the two this is.
4x10 The Loss
Another new graphic which seems to replace the solar system screen from 4x08 (or there is a third widescreen PADD). No idea what it is though. DNA bands?
This scene is great because two of them are stacked up with a bunch of other PADDs.
Troi's briefcase went up for auction, where its dimensions were given as 12 x 9 x 2 inches.
It would be great to ID this case!
4x16 Galaxy's Child
The Enterprise diagram PADD is on Picard's ready room desk in the opening scene, and Leah Brahms uses it in a later scene which provides a great view of the display graphic.
This episode adds the fourth and final graphic for the widescreen PADD and the one Elvis used for his replicas. It replaces that blurry one from "The Loss" and depicts the Tagus III archaeological dig site.
4x22 Half a Life
This is as far as I know the final appearance for the two widescreen PADDs... but they do at least go out with an orgy of PADD goodness on main engineering's pool table