Before die cast cable heads, cables used brass heads which were dipped in solder. If you can find something to use as a head thread the cable through, then fray the end open a bit. The hole in the fitting should be stepped or sort of funnel shaped with the working end of the cable coming in the narrow end, and the wider end to allow you to fray the wire open like a budding flower, and pull it back into the pocket. Solder well making sure the solder runs into and fills your floret. It's the floret with solder within it to keep from closing up that gives the job strength, and keeps it from pulling apart under load. If you do a decent job opening the wire the end will be stronger than the wire itself.

I've made cables using things like spoke nipples, or other hardware and never had a failure.