I would feel very comfortable and well served by a .38 Special Model 10, although I would rather opt for hard chrome or electroless nickel over old fashioned nickle. Too bad these finishes were not around in the 50's, at least not in the firearms field.
Make mine a 4" heavy barrel, smooth trigger, and spurless DA only hammer. Grips are almost too personal to discuss, as what works for me is garbage for someone else, but the Ahrends with no finger grooves fits quite well for my hands. Since those were not around, then I would go with factory Magnas with a T-grip. Holster is a real no brainer, a break front Berns-Martin would be as far as I looked. I actually own a break front Safariland (for a Model 10, heh-heh) made from their leather look kydex that is an even better holster than the older Bianchis and Berns-Martins, simply because it is slimmer and lighter, but I would be happy with the old school.
As a backup, I would look no further than a similarly finished and bobbed Colt Detective Special, simply because I find them easier to shoot well than a J-frame. Plus there is the added benefit of the Colt being able to use the same ammunition, although what was around in '55 wasn't much to shout about. The unshrouded barrel would save a bit of weight, and I would make sure it was fitted with a Tyler T-grip. Leather? Some sort of pocket holster.
If I was allowed to stroll a few years into the future, I would be interested in a .357 fixed sight GP-100 with the short shroud, or a Smith 581 would get the nod, with the Ruger being my first choice. Backup would be the same Colt, IF I could not find a Magnum Carry, with a Bianchi Speed Strip to feed it in either case.
Why, oh why doesn't some manufacturer take up the mantle from Colt and start making the Magnum Carry again! I would use it with .38's, but having the .357 option is a distinct advantage. The 6 shot D-frame is the perfect snub platform, and far out performs the J-frame. We have only the Rossi 461/462 in this camp as of this writing, and quality control is reportedly spotty. Even so, a 461 is next on my "must buy" list, if only to see for myself.
Otony