Most likely, your Model 28 came with the smaller stocks. Those are "Magnas", and they were standard issue on the Model 28. It also sounds like you have a set of larger target stocks for it, and they were generally post-OEM additions.
As RickN pointed out, the Model 28 has a less-polished finish, but has the same action as its more expensive Model 27 brother.
Most came in the duller blue finish. There were a few made in nickel, with 5" barrels for the Florida Highway Patrol, so if you find one in nickel, it's probably been refinished.
However, that N frame design has been around for over 100 years. Over-engineering at its finest.