I'll say this:
The 1873 Peacemaker design, based on earlier Colt single-action designs dating back to 1836, has the obvious capability of firing if dropped such that it lands on its hammer behind a loaded chamber.
This has been known for well over 100+ years, and it has in fact done so.
It's also reputed to have been fired accidentally while in a holster when a man saddling his horse swung a stirrup that hit the hammer, behind a loaded chamber.
In percussion revolver days, it was recommended not to carry with the hammer resting on a capped chamber; typically either that chamber was left unloaded or the hammer was carried positioned between chambers.
With the advent of the 1873's self-contained cartridge system, the practice of leaving the chamber under the hammer empty was soon adopted, as people began to discover the danger of carry with the hammer's firing pin resting directly on a primer.
Accidents happened, word spread, people adapted accordingly.
This is not folk lore, it's well established safety advice.
Writer Mike Venturino personally saw it happen, when a fully-loaded dropped single-action landed on its hammer & fatally shot its owner, even in supposedly better-informed modern times.
It is, as you note, the reason Ruger adopted their transfer bar in 1973, after losing a multi-million-dollar lawsuit centering around the loaded-chamber issue.
A traveling Colt armorer at a school I attended in 1993 told me Colt's attorneys were pressing hard to have Colt drop the Peacemaker, entirely because of its outdated design with no safety.
Colt kept it on as an iconic symbol of the company's history & tradition, despite their attorneys' repeated warnings.
Re the "home free" "limited production" and "purchaser assumes responsibility" issue, not entirely clear.
As I mentioned above- the bulk of the Peacemakers today are production guns, not special-order pieces.
The theory of customer responsibility would not apply there, to the best of my knowledge.
I seriously doubt it would on a custom-order gun, either, since Colt could still be sued if the owner dropped his gun & shot himself with it by carrying fully loaded.
Colt, in the three owner's manuals that came with my Peacemakers over a period of 15 or so years, dealt obliquely with the issue by including language recommending buyers not shoot the gun, since Colt considered it a collector piece.
How much that could protect the company against suit would be questionable.
I have never heard any Colt employee or rep discuss the legal protection issue any further than that Colt armorer in 1993 who also said (emphasizing AT THE TIME) that the Peacemaker's high price was due to two things- the first was that it was an expensive gun to produce, and the second was that Colt wanted to price it for the collector market who would theoretically not shoot the guns, as opposed to the shooter market, because of the legal department's liability cautions.
I have been told by Colt that with the re-introduction of the Series 70 lockwork in their 1911s a while back, their theory previously had been they couldn't, despite the market's unhappiness with the Series 80 lockwork, revert back since once they'd established the "superior safety factor" of the new design they'd be opening themselves up to liability in again producing a "less safe" version.
Reverting would have been a step backward, safety-wise, leaving them open to increased liability if somebody shot themselves accidentally in such a manner that a claim could be successfully presented in court that the accident could not, or would not, have happened with a Series 80 safety system.
At some point somebody decided that liability inherent to producing a "less safe earlier generation" pistol could be reduced by calling the new Series 70s "replicas" of older Colt models, in which the buyer theoretically accepted at least some of the risk by deliberately choosing the "less safe replica" gun when he or she could have chosen the safer models.
And, the 70 Series was brought back.
I do not speak for Colt in any manner or form in saying any of the above.
I don't know what their current thoughts are directly relating to how they feel they can address a lawsuit arising out of the Peacemaker's antiquated design.
The theory could very well be something along the lines of "We told you not to shoot it in the manual, you should have known the gun could do that, we warned you about it, it's not our fault you blew a hole in your butt or leg by carrying six-up and dropping the gun."
I would not think "limited production" or "custom guns" would transfer any burden of responsibility off Colt's shoulders & onto the consumer.
I'm not even sure the "replica" theory would, entirely, if pressed in court.
Best I can tell you.
Denis