Thanks for the link IrishMedals.
I will certainly try to get to the museum on my next trip. Oddly, I went there a few years ago just to look around the castle buildings but did not know about the police connection at that time and didn't spot that the Garda Museum was there.
Before I go there, I think maybe I ought to check out whether William and Michael were possibly ever in the police too.
Makes me wonder if other O'Malley police were related too - perhaps cousins?