[Hallicrafters] Bumblee Caps.

[William Hawkins]

In 50 years of electronic troubleshooting, I have run into those caps in everything from an RCA videotape recorder to a $15 Philco table radio.
They were all bad.  Shorted, cases split, off value, leaky and more.
I've never seen a manufacturer's name on them.  
I've been told they were made by Sprague but I find that hard to believe.
The Sprague "Black Beauty Telecaps" were an entirely different product and were high quality capacitors.
It seems to me that the bumble bee's must have been very cheap OEM products and were sold to many different companies.
Gibson did use them as tone caps in their guitars and somehow they gained "cult" status.  I have a 1956 Gibson Console Grande steel guitar which, when I bought it 8 years ago, still had the original bumblebee
cap in it.   It was shorted.   Probably they lasted longer in guitars because there is no significant voltage there. 
Sorry that Hallicrafters used them too.
There is a lot of "folk lore" among guitarists about those caps.
Blake
N4YCQ