WOW!!!
That's one of the strangest, coolest Power Wagon Fire Trucks I've ever seen!!! I want one!
I'm gonna go with HOMEMADE. The Barton pump was commonly provided for self-installation (the directions for the pump include somewhat detailed how-tos for mounting the pump). The Hale pump on the rear is unique, never seen that model before. The rear bumper/ground sprayer bar also seems very homemade, especially how it's plumbed. The additional pump is redundant, as the Barton pump was designed to be engaged while the truck was in motion, though the fire service has always been into redundancy for reliability.
Everything about the truck looks like some very creative, high-level fabrication from a department that wanted to add a brush truck to their line-up, and had a Power-Wagon chassis to build it on. It's a really good looking truck, and I love that it's got single wheels in the rear. It's sorta like a Jeep on steroids.
-Michael
