Crenwelge
The lever is on the steering coluem on the "67" GMC 9500 Fire Ladder truck.
No brake knob on the dash.
When Fire Trucks were fitted with beds, the out fitters would make every thing work.
Your thoughts on a seperate trailer brake system makes sense.

Sunday afternoon, time to take the ladder down.
and see if there is any markings on the lever.

Thanks
2-Ton

1967 GMC 9500 Fire Ladder Truck
"The Flag Pole"
In the Stovebolt Gallery
1946 2-Ton grain truck
1946 3/4-ton pickup,
1953 1-ton pickup
1957 1-ton flatbed dually,
1954 Pontiac Straight Eight
Of all the things I've lost in my life, I miss my mind the most!