I own two Heritage guitars, a 1998 H150-CM which was factory-equipped with a Nashville bridge and a zinc stop tailpiece, as well as Seymour Duncan 59's. I bought it second-hand from the dealer who had a special run made and their customer traded it in. It was also fretted with 6100 wire and no nibs. Possibly done by prior owner, but they look factory to me.
I swapped the zinc tail piece and Nashville bridge for Faber ABR and aluminum, and replaced the heavy Rotomatics with exact fit Gotoh tuners and lost enough weight to bring the whole thing nicely under 9lbs.
I have a 2001 H535, which I bought recently in near-mint condition. It came with the usual Schaller hardware and HRW pickups, the medium jumbo fretwire and nibs. I've tried a few combos of ABR bridge and tailpieces, including a Nashville, anylon saddle ABR, and a Faber tone-lock ABR. I have an aluminum stop bar on it. I couldn't lock the Faber tail on, since the stud holes are a bit too shallow on this particular 535.
Honestly, I can't say any of the bridges were ground-breakingly different in tone. If anything, the tune-o-matic bridges are slightly brighter sounding, and a little bit off my target of getting more of that mid-range forward semi-hollow sound.
The nylon saddle ABR bridge really didn't sound materially different than the nashville, nor the metal saddle ABR.
I'm considering just putting the Schaller stuff back on it. Like I said, they're in near-mint condition. Kind of weird looking and not exactly what I'm used to. But I can certainly play them well enough.
I played a Collings I35-LC the other day. Holy cow, that thing sounded absolutely amazing. Totally nailed the tone. Collings uses the heavy zinc tail and ABR from Kluson of all things. Whatever they did with the wood though really hit the mark. Acoustically it instantly had that sound.