"Did we frighten you with our 'You've been put in notice' video and our lawsuit? Just give us some money, and we won't do that to you."
measuring the guitar for scale length can be a bit more complex than measuring a single distance,(ie PRS & DUESENBERG) but math is ultimately your friend in this process. ABRs can be placed completely by math, after the neck is set.Yes all LP's will be listed at 24.75, and have been for as long as I can remember ( at least pre Henry). However, the reality is they don't all measure that way. The reason people observe something different than the Gibson spec is because they actually measure the instruments, just as PRS did when he was designing the Models in question. The old Kalamazoo Gibsons that we covet were all made by hand and had a great deal of variation in nearly every area, whether it was the carve of the dish, the winding of the pickups etc, who cut the nut etc... so while the target may have been 24.75...it didn't always work out that way. PRS with it's precise CNC can set a target of .594 and be pretty confident that they can hit it within the travel of the bridge saddles as the variances are much less.
Im no luthier, but for years I've researched building my own LP as I couldn't find the perfect one for me. The first thing I noticed was that none of the routing templates included the bridge placement. I soon learned that this was because bridge placement was determined while the guitar was tuned to pitch, with the bridge sitting on a temporary fixture which allowed for movement fore and aft to accommodate proper intonation across all strings and still having saddle travel available for future adjustments. This is why the bridge is not always in the same location on the classic bursts. A good way to see this is to grab your copy of the fantastic reference by Yasuhiko Iwanade "The Beauty of the Burst", which details a number of 58-60 Bursts. The formatting of the book includes a full body shot on the left pages throughout, allowing you to treat it like a flip book. And you'll see that the bridge position, relative to unmoving bridge pickup route, is not constant at all, and in fact moves at least as much as the .25 tolerance difference we are discussing. I suspect PRS discovered in his research that the LP's he preferred from a sound and playing standpoint averaged much closer to the 594 spec than the .75 stated spec. I assume harmonic nodes relative to pickup location can have a large effect with even a 1/4 inch deviation.