A quick trip through the gallery finds one 20,13,16 Rogers set belonging to PurdieShuffle. Do any others have that configuration?
Years ago I had one in blue sparkle. It was definitely a factory set.
I don't see this arrangment very often so was curious if there were many ordered. I also don't see it as an offered configuration in the two catalogs I have (67/68 and 70).
I note that it was popular with Gretsch, Slingerland and Leedy and shown in their catalogs as Bop, Gene Krupa and Shelly Manne.