About your vintage headphones, you might give a call to the OLD TECHNOLOGY 
SHOP in Seattle, WA, Steven von Talge, Prop.  I have visited the place many 
times during my business trips to Seattle.  There is a lot of 1930s and 1940s 
stuff there and Steve is a good guy to deal with.  I imagine you might end up 
buying a complete headphone set rather than a replacement cord.  I suspect 
that what you have is an ElectroVoice set.  I have the Steve's calling card 
in front of me now.  Believe it or not there is no area code printed on it, 
but the Seattle number is 527-2829.  Open 12:30 - 6 Wed-Sat and 2-6 Sunday.  
Good luck.
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