Thomas, I pick them up at York from MTH which is why I don't have the part number. No doubt some of the MTH techs know the number. Its sold with a connector at both ends, one straight and the other a right angle. I cut off the right angle one. MTH also sells a tether with just one straight connector and bare wires at the other end but its meant for diesels and for reasons only known to MTH uses a different color code than the steam tether????
By using the double ended one I can easily spliced the new tether to wires in the tender, no ringing out of the wires to the connector and keeping track on paper required. Its a few bucks more but worth it both to me and next guy.
PS, I found an old email from Midge. I am pretty sure the part number for the double ended tether is BC-0000217
Pete