Strange set of RCA EL34s. Any idea about the design?

My ST-70 came (old family friend was moving) with four of these RCAs.   They appear to be double halo but I can understand or have seen ones with the getter on the side.  

Anyone have any knowledge of the story behind these types of el34s?
Thanks.  
Chris


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From the Brent Jessee website:

EL34 / 6CA7 RCA, GE, Sylvania, etc. "Fat Boy"

The "Fat Boy" USA made tubes were produced primarily by Sylvania and GE. These have a much wider glass bottle, a black base, several round holes in the plates, and two large top getter rings set at an inverted "V" angle. The GE has the numbers etched into the glass, while the Sylvania used a dark grey paint with the words "USA" below. These "Fat Boy" tubes are very nice, and are still attractively priced. You will find them in RCA, Zenith, GE, Sylvania, Philips, Philco, and others, but they are all made by either Sylvania or GE.

http://www.audiotubes.com/el34.htm

Those tubes were definitely not made by RCA - from the tube number markings on the tube glass in the first (top) picture they were Sylvania made.