I'v started the chains anyway there all off now and i'v just removed the oil nozzle and mine has NOT been replace, and as goatboy says we both had cut outs on the bolt on the side if the head!!! So be carefull this may not be a surefire way of determining if the nozzle has been changed.
The chain is well oiled but i'm so glad I'v done it now!!!!
Hopefully i'll be able to put it back together tomorro if the bit turn up!!!.
will let you know tommoro