Thanks for the advice guys

It sheared flush with the plate and what a pain in the *ss it was to get the rest out - omg!

After a MarioKart stlye dash up the M6 to Stoke i got a replacement (still plastic - but due to time restrictions/work - it was the only option)
After a nerve racking tightening of the new part - connected it all up - no leak - just returned from work , so its done 60 miles and alls good - job done
Thanks again
ni