Apologies for side-tracking from the original subject 4506, but this is a very curious photo you have uploaded, can you share more about that? You reference an 845 but I'm not sure what you have shown in this picture--
The hammer absolutely looks like an 845 and yes, the forward serrations do look like the second run "Model of 1998" 845, however the trigger is
way out forward, to the point where it suggests DA/SA, which the 845 is absolutely not.
Further muddying the waters, if that were a second run 845, it should have an etched Performance Center logo on the right side of the frame and further still, the round hammer block safety area (where an ambi lever would be if it weren't a 5" PC Target gun) should be flat black on an 845.
Gotta love Smith & Wesson! Almost makes you think those guys did stuff like this just in hopes that it might drive a few collectors bonkers one day down the road...