I have a CD that I acquired from the HO scale model company Westerfield a number of years ago. It has a selection of AC&F builders photos and jpg copies of an order list record of ACF orders 1899-1957. As I recall there was a local NMRA convention and vendor hall in Long Beach, CA that I visited on the last day (public/non-NMRA member day) of the vendor hall; I got the CD at a discounted "end of the show" kind of price. For ease of accessing the order list, I copied the jpg images into a PDF file.
This is a snip-it from it showing the entry for order Lot #8687.
I cannot make out the name of the Smelting & Refining Co. that ordered the cars. The difference from June of 1919 to 9-1919 would allow for the construction of the car(s).
Brian Norden