Teeter :
Thanks for that. The commentary while driving is a skill I was taught many moons ago, but no longer need or have anyone to impress with it so it's scarcely used.
Looking around at what's available there also seems to be some disparity between what I hear and do in the a/c ( have a guess, ends in R22 ) and what the books say - I'd rather write my own from scratch if there is no alternative but if there's something which fits the bill . . .
Any ex- or serving beefer got a copy of something I could have a gander at - liquid thanks available, and it's not like I'm a million miles from MW.