The last narrow gauge locomotive that received the new flying Rio Grande herald was apparently K-27 #463. It spent a lot of time on the RGS in the early 1940's so may have missed its appointment with the painters.
Here a photo from the Denver Public Library collection taken by Otto Perry on September 24th, 1943 at Ophir:
K-27 #463 in 1943 with Button Herald
By 1943, all other narrow gauge engines (for which photo documentation exists) had the flying Rio Grande herald.
Here's the next photo I could find of #463. It was taken on May 25, 1945 at Montrose by Charles Winters (part of the FOCTS Dorman Collection):
#463 with flying Rio Grande in 1945
Sometime in the intervening 21 months it was repainted.
I don't know about standard gauge power, but I have a hunch that they were all converted prior to 1943...