I'm a bit bewildered by what is really wanted here. Please explain by answering these questions.
Are you trying to create an "Express Reefer" ?
Is it just for display purposes ?
This can easily be accomplished by mounting B'mann or LGB American style passenger trucks on an LGB, or USTrains wood reefer....the ones that have a simulated wood underframe, and truss rods. Both are about the same scale, whatever that scale is.....The trucks fit very well, without any problem, except that they do not work with the truck mounted coupler arm, that is easily removed.
..After removing the coupler arm from the trucks, a Kaydee 1906, or 820 body mount coupler is easily mounted on the car, using Styrene shims. You might have to cut a bit on the ends of the car to get the couplers to fit at the correct height, but does not in any way destroy the car's appearance.
I have modified a number of these cars, in this way, and all of them operate very well in passenger consists.
If the person that is trying to make this car into a static model, for display use, doesn't have the will or skills to do the job; I'm willing to do it for him/her....free of charge. Just send the car to me, and pay for the couplers, and shipping.
Although I don't know of any Narrow Gauge express reefers, riding/equipped with passenger/high speed trucks, the cars when modified, look very good in a standard gauge 1:29 heavy weight passenger car consist, and resemble early wood framed exoress reefers.
I don't do pictures, or I would show the ones we use in our operations on the IPP&W, here in Ottawa Canada.
I wish people on this web page would use their real names, and could easily be contacted off line......
Fred Mills.
millsf@sympatico.ca