913, 918, 90, 91, and 925 Commercials
I suspect some of you remember the commercial models referenced above from the 1940's and 1950's. The 925, I believe, was from the 1930's. The only one of these I've seen is Stan Kann's.
In my vintage vacuum collection, I have several Model 913's (made in England; a 918; and a 91. I believe the 90 and 91 were made in the U. S.
Jeff Parker and Tom Anderson, correct me as needed on this.