I've been away from this forum for several months due to computer problems and a torrid affair with 1911s, but recently dug my Model 28 out of the safe to get reacquainted with it after winning a Simply Rugged Sourdough Pancake carved by Rick Gettlein in a raffle, that fits the old HP perfectly and is VERY comfortable.
This is a 28-2, s/n N5928xx, 4-inch, with a semi-target hammer and smooth combat trigger. I bought it at a hock shop several years ago for what I thought was a good price until I found that it had a .014 cylinder gap. Nastiest gun I ever shot. Serial range puts it about 1979, when the QC left much to be desired.
After worrying with it for a while, I called the factory and spoke to a very nice lady in the repair shop. She said that it should not have gone out the door like that no matter when it was made, and to send it back. They set the barrel back, recut the forcing cone, and set the gap at .004. Don't remember now what it cost, but it wasn't much and was well worth it - this is now one of the finest shooting handguns I have ever shot. I bought a sound but battered and scarred set of walnut targets for $5.00 at a gun show, sanded them down, recut the checkering, and refinished them with tung oil to replace the ugly rubber Hogue grips that were on the gun. It's a mighty fine looking rig now, and I'm learning to appreciate Model 28s all over again.