That Pierce pumper, anyone have a rough idea of the era of it?
I believe the cab was introduced in the early-mid 90's. Here is a 1992 model with a similar cab:
https://www.firetruckmall.com/AvailableTruck/13461/1992-Pierce-Lance-PumperThe AC may be a late addition and the pump may be a re-body.
COEs like this go back further into the 1980's. Many of the older 2nd hand trucks you see today have been rebuilt at some point. A major modification was to fully enclose the cab. This was done in mass in the early 2000's as nerf bar restraining devices were banned and a fully enclosed cab helped keep the weather out. Many fire departments had extra money due to Homeland Security grants. The second reason behind enclosed cabs was it could be used as a rehab in a pinch. Thats where you'll see AC units attached to the cab.
The body is fairly upright and compact. The end is squared off. Hoses are covered. equipment panels are roll up rather than swing out. This indicates it was probably based on a 2000-2010's prototype. To backdate, I would do the following:
Remove the roof top AC.
Remove the secondary AC over the pump unit - I'm not sure why this has both, but it could be an air compressor for air supply.
Flip the etched roll up doors around to make swing-out doors.
Open up the hose bed from the top.
That would bring it back to roughly the mid 90's. If you wnat to backdate it further, you can:
Open up the small cab windows.
modify the radiator opening.
Add angle sheet to the rear of the hose bed like this -
http://firetruckresource.com/wp-content/uploads/2018/05/IMG_4166-876x535.jpgThat would bring it close to a very early 90's version:
https://www.firetruckmall.com/AvailableTruck/12836/1990-Pierce-Lance-PumperThis design had very long legs in general.