Howdy
Dunno what's going on at the bottom of the grips, looks like the bottom of both grips broke away at the alignment pin hole. Fairly common. Looks replated to me as the trigger and hammer look plated. S&W never plated their hammers or triggers. Hammer and trigger should be Case Hardened, trigger guard should be blue or case hardened. But replated guns can be nice too.
First remove the cylinder by lifting the top latch, opening the gun, and rotating the cylinder the wrong direction while applying slight pressure backwards. There is an interrupted thread on the arbor that keeps the cylinder on the arbor. Rotating the cylinder backwards with slight backwards pressure engages the thread and allows the cylinder to be threaded off the arbor. Lifting the latch allows the cylinder to slide up past the lug on the underside of the latch. It will be obvious.
Removing the side plate is pretty much the same as taking the sideplate off on a modern S&W. Remove the grips, then remove the one screw in the center of the side plate. I don't remember exactly right now, but that screw may actually be a nut, disguised to look like a screw, as with the modern guns. The screw/nut usually sets into a counterbore on the old Top Breaks, holding the side plate in place.
Anyway, once the screw/nut is removed you can pop the side plate off exactly the same way as with a modern revolver. No, nothing is primed to sproing off into the wilderness when the side plate was removed in these old guns. Not a bad idea though to rest your thumb lightly on the side plate as you whack the frame, so the plate stays put. Next step is removing the main spring. You have to compress it to relieve it from contact with the hammer spur. I use a pair of pliers that opens rather than closes when the handles are squeezed. Just noticed there seems to be a strain screw on this gun. Relieve the strain screw first before attempting to remove the main spring. Note: getting the spring back in place is always tricky as it involves compressing the spring with one hand while maneuvering the hammer and hammer stirrup into position with your two other hands. It usually takes me a bunch of tries with any Top Break Smith. But it is easier if there is a strain screw to relieve the bend of the spring. Not all Top Breaks have that feature. Once the main spring is out you can maneuver the hammer and hand out. That's as far as I usually go with Top Breaks, removing the trigger and cylinder stop requires driving out the pins they ride on and I don't like to go that far. You can do a pretty detailed inside cleaning with those parts still in place. I don't like to remove the barrel, some of them have pretty tricky mechanisms for ratcheting the ejector, some don't. You can lubricate the barrel hinge pretty well without removing it. I just leave it at that.
I heartily recommend you buy this book:
http://www.oldwestgunsmith.com/mybooks/af.htm
This book will take you through complete disassembly and reassembly of many old guns. An invaluable resource for the owner of old guns. You can buy it from Dave's web site, or on Amazon.
