Hooking a JTAG cable to most models of 2Wire requires a card edge connector: 
The pitch and finger count of this connector is unusual, and very hard to find. None of the major suppliers keep the component in stock.
Future Electronics of Quebec City is an exception, and Future also accepts small orders. 
Behold! A small miracle has arrived, courtesy of FedEx, and just in time for Xmas!
It is the GCE08DHRN..
The fit isn’t perfect. To squeeze the connector into the tight gaps on some boards, a groove needs to be filed along the sides of the connector. It will certainly do for now though. Many thanks to Patti at Future for sourcing it.
The connector has now been made into a working JTAG cable. See