I've done a fair bit of research into this, the UK seems to break more than it's fair share of tghese .....
1) Correct size plastic knitting needle - can't remember size, but there is one just right, top as found or customise !
2) Wooden kebab stick/skewer - these are very strong. Blunt the tip, sand, varnish or customise (do a few !)
3) Explore local £land/dimeand cent/discount stores. They have all manner of weird stuff, usually including some sylii/uses for different game consoles etc..
And yes, the 650 is same stylus, which breaks at either end as far as I've heard, and has even been bent in the centre metal bit - although there is a cheaper white plastic one going about, perhaps it's one Sony make for something else ?
Hope that's of help..........