Some Hats Trivia

What's with these two hats that made them so popular? Any more sightings?

A floppy hat with buttons for trim seen on Nellie Conway (Joan Lovejoy, left)
in #204, TCOT Woeful Widower and on Mrs. Stallman (Geraldine Wall, right)
in #250, TCOT Wrathful Wraith.

A boxy hat with rickrack (trim) and a bow seen on the same pair, left and right.

The rickrack returns on Mrs Webb (Meg Wyllie) in #256, TCOT Bogus Buccaneers.

[Trivia][Perry Mason TV Series]