Reading between the lines: "young" Clary goes after the wife of a fifty-nine year old man; ergo, the wife is substantially younger than her husband - stands to reason, don't it? No, it's not stated explicitly; this is what interpretation is about.

Of course, other interpretations are possible: maybe 'young Clary' is 87 - but 'old Clary', his dad, is 102 ...

(BTW, is there anything interesting about the how 'Coward of the County' came to be written? Because I'm perfectly willing to take your word for it that it had nothing to do with either Rogers without searching out an interview.)