There was no typeface change for “ż” - the other typeface is sometimes used now as it was 30 years ago. See the foto at Wikipedia: https://en.m.wikipedia.org/wiki/%C5%BB
> It represents the same sound in the Polish alphabet, remaining in active usage by some as an alternative for the letter Ż (called "Z with overdot").
> In Polish, the character Ƶ is used as an allographic variant of the letter ⟨Ż⟩ (called "Z with overdot") although once used in Old Polish.
Funnily, there's a counter-argument to "Straż Miejska" from article you linked, with "Straƶ Miejska" in another Wikipedia entry[1] :)
It may depend on the region (I was raised in the eastern Poland) but I also remember that in the primary school we used a different symbol for the letter "s". But only in hand-writing while any printed "s" looked like it does currently. I'm unable to find the UTF-8 character resembling the hand-written version.