So I just picked up this nifty little gun yesterday and I've already figured I need to ask two questions:

1) what is the point of being able to bypass the half-cock notch?

The hammer has this little thing (maybe called the "hammer fly" by Numerich?) that gets pushed up and out of the way when slowly cocking the hammer that allows the rear sear to catch the half-cock notch, but once the hammer is pulled back a bit more, that thing drops back down and allows the rear sear to slip by the half-cock notch if, say, I slip my thumb off the hammer or if I were to de-cock the hammer from single-action.

My guess (figured as I was typing this) is that it prevents the half-cock notch or rear sear from breaking if my thumb were to slip while cocking the hammer, or as a belt-and-suspenders sort of guarantee that the rear-sear is out of the way while the hammer is dropping to avoid a situation where the gun won't fire if I need it to. So then really, the point of having a half-cock notch at all is a) to be able to carry all chambers loaded, and b) to be able to open the gun.

2) The single-action has a bad push-off condition, so bad that it doesn't even stay cocked at all (or maybe it will, but as soon as I breathe on it the hammer drops). Are there any reputable gunsmiths that work on old guns like this? I found Dave Chicoine via a Google search -- anyone have any experience with him?

Thanks!

Edit: looks like a lot of us here have had good experiences with Mr. Chicoine. I'll send him an email about my issues and see what he says. Thanks!

You figured out the 1/2 cock situation correctly. Many people have had good experience with David Chicoine, I haven't. However, adjusting the action on your gun is not rocket science. Often a good interior cleaning of a gun as old as yours cures problems like you describe. A 100+ years of crud, grease and dirt are probably in there and need to be removed. Do that cleaning and you may not need Mr. Chicoine's services, which may cost you more than you paid for the gun. Good Luck, Ed.

I'm very intimately familiar with the innards of modern S&W revolvers, but not so much with the earlier hand-ejectors, and even less so with these top-breaks.

I did, however, open it up upon discovering the push-off condition, took out the hammer, and spent the better part of the next two hours trying to figure out how to put the hammer back in (eventually got it, but that was quite frustrating). It looked fairly clean in there, especially the sears -- it was stored pretty well before it came into my possession.

I'll bet you'd be right about the cost of having Mr. Chicoine fix it being expensive; I gave $150 for it, and having him fix it would probably double that.