Hi can anyone here with access to a 13000 series Missouri pacific caboose confirm to me if the company actually had a retainer valve installed of the control valve, it appears to be a AB valve.
I have access to 2 of them, and neither have retainers, on actually had a cast whistle which I as able to clean up and restore. Considering if the road didn’t have a use for the retainers and simply ran their cabooses in direct exhaust, maybe they simply didn’t install them.
Thoughts?
Thanks for your help.

Also does anyone have photos of the belt drive, battery box and alternator installed or available for sale or donation to a restoration project?
Thanks.