As far as I know, 1974-1975 cop Monacos all had panels that looked like these:
They've been called "CHP panels", and were used on 74-75 CHPs, but they were also used on:
1974-1975 dodge monaco and plymouth furys of the following kind: - usa cop cars - usa taxi cars - canadian monaco specials (of which canadian cop cars were a subset)
In the USA, I believe it was only offered on cop-cars and taxis. The USA base civilian monaco (the lowest style class available) had wood trim panels. The Canadian had a lower-style civilian class (the Monaco Special) than the lowest civilian style USA class, and this had the cop / taxi / no-wood trim panel.
It looks like Canadian monaco cop cars were always Monaco Specials, but civilians could also get monaco specials.
Here is cop king-of-the-hill 74 monaco special:
and civilian king-of-the-hill-little-brother 75 monaco special:
pics of Ghostbluesman's 1975 police Monaco:
1976+ cop Monacos had panels with wood trim, like: