Librarian, NMAH Branch Library,Smithsonian
I think you might try the folks who publish "Crown Jewels of the Wire",
a monthly newsletter for insulator collectors. This library subscribes
to this and the extent of their knowledge on insulators is impressive.
One can write to: The McDougalds/5N941 Ravine Drive/ST. Charles, IL
60175; their phone number is (708)513-1544; they published a reference
work for collectors called: " Insulators: a history and guide to North
American glass pintype insulators" and I think there are other such
guides that the McDougalds make available.THey would probably be glad to
help.
 
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