>I found the code stamped into the right end of the drive axles, around the base of the steam dome, and on the side rods.
When I'm next in Skagway I will look in those locations on 195
>As far as the 138 number, maybe baldwin built engines similar to the #190class for other lines,
The MacArthur design was unique, Baldwin didn't build any locomotives to this design previous to 190.
> or maybe they picked up the classification from where alco left off. Could #190 be the 138th built by both companies?
#190 was the 91st Macarthur, assuming they were built in sequence by USATC number, which is likely not true because ALCO was building MacArthurs at the time Baldwin started building them in '43. Baldwin got the order because ALCO could not meet production requirements for the meter gauge loks.
When the need for 36" loks for the WP&YR was recognized, the order for the 36" loks was given to Baldwin rather than interrupt ALCO's meter gauge production. Baldwin had previously built 2-8-2s for the WP&YR in '38 #70 and '39 #71 so perhaps it was decided that Baldwin had more experience in this case. Unfortunately the short sightedness of the War Dept had Baldwin build MacArthurs for the WP&YR when 70 class loks would have been a much better design for the White Pass, and no doubt would have been kept by the WP&YR long after the war and would have likely delayed diesels on the WP&YR until the late '60s.