Mont Switzer wrote:

Bruce: If you only need one Monon car it probably should be a 1937
AAR car,
450 of which arrived on the Monon in 1941 and 1942.

Per page 488 of the January 1943 ORER:

Desig IL IH Cu. Ft. Qty.
#2000-3600 XM 36' 6" 8' 2,482 615
#9000-9449 XM 40' 6" 10' 3,710 450
Total Boxcars 1,065

Monon's 1,065 boxcars was 0.14% of the National Class I RR Boxcar Fleet
or about one in every 700 boxcars.

Tim Gilbert