"Bullitt" shoulder rig

[Superabound]

I was thinking of purchasing a Safariland vertical carry holster for the Colt Detective Special (recognizable as the holster Steve McQueen wore in the movie Bullitt)from a guy online, and i was just wondering if there was a chance anyone here has had personal experience with one. Basic stuff like how reliable and solid the retention system is, how comfortable it fits, things like that. I was also wondering how it specifically would fit S&W J-frame revolvers like the Bodyguard 38 and 340PD.

Thanks in advance for any information you might have.