S&W Serial Number Help Please

[ptrumble1]

Have a Mod 10(38 Spec) with 9D65xxx and a Mod 19 (357)with K345xxx. Both have 4" brls. The 10 is a heavy Brl Round Butt and may be a bit unusual I have heard? My Standard Catalog of Smith and Wesson is in the mail but not here yet, Thanx, Tom in Fl. USA

 

[SaxonPig]

Just guessing I'd say 1981 and 1958.

HB and RB would be an unusual configuration.