Frigicar mechanical refrigeration car model

Over the past many years I have accumulated a fairly large quantity of card stock wood style billboard reefer car sides.  For the most part I have no intention of using them, but there was one set that intrigued me.  It was a North American Dispatch Frigicar set with the designation "Mechanical Transit Refrigeration".   I did a serious amount of Google searches to find out something about these cars.  I am reasonably competent in these kind of searches but information was hard to find.  What I did find was a gazillion ads for a Missouri Pacific Frigicar poster and mentions of a Train Miniatures kit that is apparently not accurate.  I also found mention that a book I once owned (The Great Yellow Fleet) had a little info.

So - here is what I have come up with.  Apparently the Frigicar company created these mechanical refrigeration cars starting in the late 1920's and were gone by WW II.  The cars used a drive off of a car axle to operate an ammonia based refrigeration system, possibly with an internal brine tank, a condenser on the roof, and no ice bunkers, thus likely had no ice hatches on the roof.  Using this sketchy information I built a model which is my best guess of what the cars looked like.

I used an old style wood block roof, ends and floor.  Since I had no information on the ends I decided to make wood ends as it suited what I was doing.  I put an end access hatch on the refrigeration unit end with a plastic corrugated scrap piece on the roof for the condenser.  I put two roof end walks on since there were no reefer roof hatches.  I added some 3-D door hinges on the sides.  After the model was complete I added some chalk weathering as I cannot stand shiny new cars ( or structures).  Below are a few more views.

Although it is a little dark you can see the access hatch on the lower right of the end.

Wether this is accurate or not, I am pleased with it.  You may note that I clip off the Kadee coupler uncoupling pins as they look awful and I do not use them.

As a side note, apparently one of the Frigicar executives installed one of these mechanical refrigeration systems in the trunk of a Packard automobile.  That was not real successful as the cost was really high.  There was also an issue with the freight cars as ammonia gas is poisonous and leaks were dicey.