As a follow on to my requests for assistance and advice I sought the assistance of one of the very best. Darth Loo Knee arrived today at 07:30 and 12 hours later had changed both head gaskets plus all of the other ancilliary components associated with the job. All genuine GM parts too - no aftermarket crap. Nothing left to chance and nothing done other than professionally. Anyone requiring a job to a high standard and at a very reasonable cost you can have absolute faith in this guy. Quite apart from that I also found that his knowledge of the Migs was astounding, not a bull******* like many who post appear to be, and freely gave any advice I requested. We had a good laugh at some of the bum irrelevant advice proferred on the forums. Only the guilty can take offence at that comment! A very pleasant experience without any problems or bodges. Briiliant - and I will definitely be a returning customer whenever the need arises.
Thanx Daz, for the work and banter!

Cheeeeeers m8, now enjoy your holiday!
Funnily enough there were no PINK rags and definitely no RA.

Ray