If I recollect correctly, the Tallfolk halflings were inspired by Merry and Pippin in the Lord of the Rings; their exceptional growth was a side effect of the time they spent with the Ent, Treebeard. Other than that, there wasn't any difference with other hobbits. I don't have my old 2e books available to peruse, so I'm not sure what other nuances were included to differentiate Tallfolk from other halflings.
Well, I can take a look at some of the older books, so let's see what I can dig up... I'm sorry for only listing these sources, I'm not sure where else the Tallfellows showed up.
AD&D Monstrous Manual:
Can speak elven and enjoy their company, can become 6th level fighters if their Strength is 17, recognize secret doors on a d6 result of 1 like elves, +2 to Surprise rolls in forests and woodlands.
Complete Book of Gnomes & Halflings:
Recognize Secret Doors and Surprise bonus as above, -1 Strength, +1 Dexterity or Wisdom, increased Ability Score Minimums (Dex 8, Con 10, Int 6, Wis 7, Cha 5) and Maximums (Dex and Wis 19).
3.5 Monster Manual 1:
Replace the standard halfling +2 Listen check racial bonus with a +5 racial bonus to Search, Spot and Listen checks, sacrifice the racial bonus to Climb, Jump and Move Silently with the ability to detect secret doors like an elf.
So... yeah, this is what they were like before 5th edition. Lorewise, they're similar to Stouts, with implied descent from the union of halflings and elves, much like how Stouts are reputed to be halfling/dwarf crossbreeds.
There's also the more martial/nomadic Stronghearts, who showed up in 3e's Forgotten Realms Campaign Setting and Races of Faerun. In the former, they traded the halfling racial bonus to saving throws for a free feat, whilst in the latter, they were just basic halflings with favored class: Rogue.
I wonder... I'm sure there's a way to get the Tallfellows to work, just not sure how.