I found the plans for this car (but no prototype photo) in "Train Shed Cyclopedia No.5" (1940). It was definitely CNJ. Just preceding the plan are two photos of similar (but NOT at all identical) cars: NKP 65018 and B&O 450200.
I expect someone sent the drawings to Korea--"No problem. What should we paint it?" And then the NKP and B&O photos were sent. Or, more likely, the whole book.
I checked out the CNJ car series (89000-89199) in assorted ORER's.
It was in January 1939 as that full series.
In July 1945, that was still true. There was a listing for CRP, but not for this series. Still all CNJ.
In October 1947, there were 119 CNJ and 81 CRP.
In October 1950, there were 14 CNJ and 186 CRP.
In July 1956 and April 1961, there were 199 listed with CNJ/CRP (not separated)
In January 1965, 22 CNJ
In October 1966, 3 CNJ
In April 1968, none
Probably much more than you wanted to know, but that 1947--1950 flip in number count is somethin'.
Thanks, all, for your help,