I reviewed it in the latest Shooting Sportsman and came to very much the same conclusions as Joe. While it takes some patience to develop the right "ear" and the explainations are somewhat vague in places, it has to be the most comprehensive documentary on the repair of British shotguns ever likely to be produced.
I wish I had it 25 years ago, and the current aficionado should be delighted with the opportunity.
Warning, it is Very long, over four hours and best to be taken in smaller doses...
you'll love it Pete. When viewing, don't look for the critisisms, imagine the enormous person investment from Jack.