I need some very stretched BS08B chain for reverse

Have emailed Mike re this so thought I'd post it for everyone else's enjoyment !  a dull photo of three bits of chain.  (Its not normal sized chain)

 

Apparently I need some fine chain with a small head (around the pin) and with a good thin waist like SL's piece on the far right .... this is the closest i have got to getting a reverse chain on but it's just stretched enough.... so the other bits are two chunky to go round the small cogs and break.... 

Here's the tight space.... from a previous blog
 
http://goodandfaithful.typepad.co.uk/good_and_faithful_frazer_/2009/12/pesky-reverse.html