What were the dates for this version of the SP&S herald scheme. Is this post steam/1956?
Ken --
The Microscale decal set is very extensive, offering six different lettering variations, but silent on when they were initiated. Based on prototype photos, it seems that the large initials came in during the second half of the 50s -- pretty much post-steam on my layout.
I'm not a SP&S expert; hopefully there's someone out there more knowledgeable.