The 1903 ORER shows the Keystone Live Stock Express company had 548 cars, 433 single deck 36’ and 115 double deck 34 & 36’
General Offices, Philadelphia Stock Yards, Philadelphia PA
Bills for Repairs to cars sent to Superintendent Motive Power, PRR, Altoona PA.
Based on the image these are standard stockcars.
The same 1903 ORER shows the Arms Palace Horse Car Co. (on the next page) With the following listing. The image shows a much longer car, similar to the old Red Ball horse mule car model.
Arms Palace Horse Cars (crosswise stalled) #20-2500 Nos. ending in “0” capacity 20 horses
Keystone Palace Horse Cars (diagonal stalled) #315-875 capacity 20 horses
Arms Palace Horse Cars (lengthwise stalled) Combination Horse and Vehicle car #5001-5021 capacity 16 horses. Have side doors for carriages. Specifically adapted for race horses. Equipped for passenger or freight train service.
Burton Perfected Cars #801-952 capacity 16 horses, lengthwise stalls for shipping race horses, equipped for passenger or freight train service.
Arms Palace Horse Cars (lengthwise stalled) #6001-6325 (same notation about race horses)
Arms Palace Horse Cars (without stalls) #4000-4250 capacity 22-26 horses. Stalless cars with three compartments for exclusive use at US Yards, Chicago, at special rental. Should not be diverted nor loaded for local points.
Keystone Palace Horse Cars #75-99. Cars with stalls and mangers removed, for shipping hay. In Leased Service
A note indicates the Burton cars 801-952 were being relettered and renumbered “Arms Palace Horse Cars” #6001-6???
The mention in Wikipedia cites John White’s “The American Railroad Freight Car” book regarding Keystone Horse Cars.