Well that explains why the JST-SH connectors that I just received didn't work. It looks like the Molex picoblade connectors are considerably more difficult to get a hold of. I've got orders out to both mouser and digi key though. I wonder where I could find replacement springs for the screws.
The connectors I got that worked called themselves JST 1.25mm (https://www.ebay.co.uk/itm/JST1-25m...var=424484320879&_trksid=p2057872.m2749.l2649)