I want to replace the cable of a late 1980s AW IGH. I can buy new cable housing from just about anywhere, and cut it to size -- the end caps on the original housing are removable and I intend to re-use those as at least the shifter ferrule looks pretty specific. My problem is with the cable, specifically, the end that sticks into the shifter. Is there some standard to which these cable ends conform? Is there a newer alternative that will (safely!) work just as well?
Note that the other end of the cable is free and does not have so much as a protective end cap on it, so I am not limited exclusively to Sturmey Archer-branded replacement kits. Also, the bike is a 24" city bike, so I doubt the cable and housing lengths would match up even if I did buy the kit (which, to my knowledge, is made for larger Raleigh frames).
As a visual reference (thank you, sheldonbrown.com), this is the cable end I'm referring to: