Dye Throttle Leaky Fill Nipple O-Ring

[Mohsink31]

Dye throttle air system with a leaky Fill nipple. I took the nipple apart and found o-ring had deteriorated into a crumbly mess.
My problem is I can't seem to find the replacement o-ring (UR90 #006 o-ring) anywhere can anyone advise where I can find one. Or if anyone has a spare one for sale please let me know.
your help is required urgently.

 

[metalfof]

I bought mine off Ebay,I think you need durometer 90,but 006 is a standard size.