The car in question was built by Pullman-Standard in May 1953 as part of a 75-car order in lot 8117, and sold to owner North American Car Company in series NAHX 30500-30574. These cars were discussed in my RP CYC Volume 30 article with an assortment of in-service photos. The 75 cars in the order were divided into seven separate series with 6 different lessees and 19 cars without any lessee company stencils.
The P-S builder photos for this lot were obtained by Ed Kaminski, with credits to Don Obarski, and published on pages 123 to 127 in the book Pullman-Standard Freight Cars 1900-1960. All of the builder photos illustrate these cars as being painted paint for the sides, ends, and roof; black slope sheets, underbody, hopper bottoms, trucks, and probably black stencils over gray.
Five cars in the series, NAHX 30514-30518, were leased by North American to the Pacific Coast Borax Company. The builder photo of NAHX 30514 is shown on page 124 with what amounts to a letter board across the top of the car on two lines in serif-style stencils with the top line of larger size than the 2nd line.
PACIFIC COAST BORAX COMPANY
DIVISION OF BORAX CONSOLIDATED LIMITED
If my memory serves correctly, around 10 years ago Frank Hodina contacted me as he came up with a color photo of a car in this multi-color paint scheme. I contacted InterMountain and they were receptive to producing a model and created the artwork. They did a terrific job of accurately depicting the prototype car. In the 2012-2013 time frame, InterMountain offered this model in the 5 numbers, so this current offering is a re-run. Unfortunately, I cannot locate the photo and would need to contact Frank to see if he still has it.
I’m unable to confirm if all 5 of the cars actually received this scheme. In any event I’m unaware of a P-S builder photo taken in this scheme promoting the new Polybor-Chlorate.
Regarding your other question about how many in the fleet, roster data in RP CYC Volume 30 provides details of 225 new cars of the 1958 cu.ft. design, built from Oct. 1950 to May 1953 by Pullman-Standard in five separate orders.
Also, in 1952 NAHX acquired 8 additional cars built by ACF for West End Chemical Co. The fleet of cars were numbered 30000-30149, 30400-30407 (2nd-hand cars), and 30500-30574. Original lessees included American Potash & Chemical Corp. (55 cars), International Minerals & Chemical Corp. (131), Pacific Coast Borax Co. (5), West End Chemical Co. (1 new; plus possibly the 8 cars purchased 2nd-hand from West End), Kimberly-Clark Corp. (5), and Reynolds Metals Co. (6). Another 22 cars were used in a pool presumably for short-term leases or possibly for long-term leases if made after the cars were built.
For anyone interested in getting into the gritty details of the P-S lot 8117 cars, the Pullman Library has P-S contract files that include a chronological sequence of events via NAHX and P-S correspondence and other info to include specialties provided by numerous suppliers of parts such as hand brakes, running boards, trucks, etc., and their associated costs. These files may also provide specific info if P-S did the painting of one or more cars in the Polybor-Chlorate scheme.