A replacement baritone neck for a Strat or Tele will assume that the bridge is in the standard Strat/Tele location and the frets are all positioned accordingly (you normally end up with 24 frets rather than 21 or 22 as a result). No movement of the bridge is required. So all that happens is that the pickups are all proportionally further towards the bridge than on a standard scale length guitar, so will have relatively less bass content.
A purpose designed baritone might have a 22 fret neck so the pickups are spaced out more. Then the neck pickup will be nearer that 22nd fret and have a lot more bass in the sound.
Hey DB, I didn't tell the full story, but I came that day planning to start building a baritone neck and left with a pre-built one ! Most productive arvo I have ever done haha
Current Builds and status
scratch end grain pine tele - first clear coat on !
JBA-4 - assembled - final tweaks
Telemonster double scale tele - finish tobacco burst on body and sand neck
Completed builds
scratch oak.rose gum Jazzmaster - assembled needs setup
MK-2 Mosrite - assembled - play in
Ash tele with Baritone neck - neck pup wiring tweaks and play in