Thanks for that Sue. I just got back from the Island and when in the MNH library I did choose the films according to year and register. I looked for the Arch wills first as I knew they'd be the easiest. Looking for Episcopal wills was as time consuming and frustrating as ever - GL 712 for example, supposed to be 1759-61, has some 1760 before and after 1761, and it's not clear if all the books are included. I scanned carefully through the whole film forward and back without success - took me an hour - for a will which the card index lists as 1760 book 2. Packing up, I grumbled to the archivist on the desk who then produced a list that a volunteer had made of the contents of several wills films. That confirmed 'my' will wasn't on the film after all. If only I'd known of the existence of this list beforehand I could have saved myself a lot of time! Still don't know how to find where the will actually is! Unfortunately there wasn't such a list for 1805 or I could have checked if another I couldn't find was really on GL731. Well, maybe not, as I only found out about the lists 10 minutes before I had to leave the library on my last day.

By the way, the parishes don't always appear in strictly the right order - sometimes Malew papers crop up amongst the Braddan, for example.

When you go to the National Archive in London there are fact sheets, on many different topics, with step by step instructions on how to find the information you want - perhaps the MNHL could do the same