That particular part is actually not a tow cable, they are parts 35 & 46. The smaller cable, part #12, is for pulling the track back together after splitting. Tracks would be split when needed to either change out a broken or worn pad, or to put the track back on after throwing one. To replace the tow cables I have cut off the ends, drilled them out, then inserted appropriate sized picture hanging wire. Check out the ones I did for my Panther in "Goal is completion" section, 1st tank in 25 years. Now, these track cables are quite a bit smaller so drilling out the ends might be a chore, but I'm sure you can find some braided wire that size somewhere. Hope this helps.
Cheers, Dennis