Hello Tony,
Were these screw ends on UK ebay, or elsewhere. I've tried to copy-and-paste your reference, but no trace of either the trader or the item No. However, the similar product from Venhill is the right diameter and length for the drums in the 'black box'.
I have bought three on spec, and they fit a treat. There are, however, two snags with the items I have sourced: the 1.2mm cable ('rope' in technical parlance, apparently) jams in the grooves on the drums; the hole for the cable in the screw ends needs to be countersunk to permit splaying and soldering the cable as explained by Johnny BG in post #14. I wouldn't be comfortable relying on the screw when there is only a millimetre, or so, past it.
There is a company in the UK, SWR, who stock 0.6mm cable - and even thinner. They offer bespoke services,
https://steelwirerope.com so I intend to give them a call tomorrow. Watch this space.
Derek.