Chosen Solution
The original cord has frayed and come apart.I need ideas as to how to insert at the end where the phone body is, asa well as how to anchor the end that fits into the ear/mouthpiece.
Since the original cord has frayed and come apart,you could replace it using a thick wire, with a black rubber covering. such as:
You could try a thick piece of rope/string, or a charger cord could be a good replacement. Or you could try to restore the original cord, and insert the end of the cord (or a replacement)in phone body, gluing it and inserting the other end at the mouthpiece.