I actually once did a fan fiction which was a kind of "episode guide" to how the first three seasons of TNG might have went in the altered 'war with the Klingons' timeline. "Encounter At Farpoint" was all about the Klingons and Federation fighting over the rights to stake a claim to Deneb IV, "The Naked Now" seen the crew under threat from an impending Klingon attack and needing to salvage (or destroy) the USS Tchaikovsky's data logs in order to protect Federation secrets, and so on. Small but significant changes along the way.
If I recall correctly, I had Data being discovered as normal, but the events of "Measure Of A Man" didn't pan out in his favor and Starfleet got the patent to replicate him. So the Data of the altered timeline is literally an object of little value, and multiple Soong androids are used as virtual cannon fodder in the war with the Klingons.
I seem to remember mixing it up a bit RE: "Skin Of Evil". An alternate Deanna was on the Enterprise right up to this episode, but Armus kills her instead of Tasha, thus explaining the lack of her presence in the altered timeline in "Yesterday's Enterprise".