- mod 66 serial BHY251X
Book is a little sketchy with these numbers... I think this is because S&W got in the habit of "reserving" some ranges for future use. With that said, I believe you are looking at 1992 date.
- mod 64-3 serial AFL894X
Late 1984 for this one.
- mod 64-3 serial AJE608X
Confusing for the same reasons as above, but appears to be mid to late 1985.
- mod 60 serial AYP483X
January of 1988.
Model 5906 serial VAC855x
1994...I think!
My source is the phenomenal Standard Catalog of S&W, but I have only the second edition. The 3rd is "current" but also old... the 4th Edition is at the tail end of being written RIGHT NOW! I can't wait to get it and I hope it makes many of these serial number questions a bit easier to answer - and with more accurate and confident answers.
Hope that helps!