If you can't get one, then stick the end of your cone into boiling water to soften it, then screw it into your angle adaptor, then un-screw it and repeat the process until you see it cutting a thread for you.Don't stick it into boiling water for to long or it will be far to soft.
ive just sold 2 end threads to a chap down south and he said they worked a treat.
yes mate. just give me a buzzask for james 0115 9394444