According to TM's Illustrated Guide, the production data was as follows:
UP Challenger by Samhongsa 500 (First Run) . Second run 300 divided between UP, Clinchfield and Rio Grande
UP Big Boy by Samhongsa 1200. Another run numbered 4002 produced. No volume data
SP Cab Forward by Samhongsa 1500
N&W 2-6-6-4 First Run 300 units No further data
Lew Schneider