I am having trouble trying to find what this is worth.It is 48-4
four inch pinned and recssed. It also has a 22lr cylinder in its own cradle. The case hardening on the hammer and trigger have been buffed. serial #77k9849
I have never seen a model 48 with a round butt. My guess is that someone round butted it. The backstrap should be serrated all the way down. If it's not the gun has been altered. It's value would be as a shooter only, especially with the casecoloring buffed off the hammer and trigger. This removed the surface hardening of the metal.
A model 48-4 would have come from Smith & Wesson with a square butt and case colored hammer and trigger so those areas have been modified. I cannot see the finish well enough to figure out if it may have been refinished but with the mentioned modifications I would be suspicious it's been refinished. The grips on the gun look like unmodified K-frame round butt service grips - probably. Value is hard to determine because of the modifications but the main value would be as a shooter. If the extra cylinder is numbers matching it might make the extra cylinder worth more than a non-number matching serial number cylinder in a non-modified gun but with the modifications to the gun it's probably worth about $100. I cannot see the extra grips well enough to determine their value. I think the $850-$1100 value proposed from Mike McLellan is about right if in original excellent condition and it would need the original box with numbers matching .22 LR cylinder to get to $1100. However, given all the variables a stab in the dark regarding value might be $400+ if it's refinished and Maybe $600+ if it retains original finish and is in excellent condition???