If it is impossible to borrow the films (and I have been told that any bona fide Family history soc may so so, not just LDS FHC's) then you must hope that someone has already done the research, or will do it for you out of charity, or pay for a researcher. A holiday in SLC might also be an option.

I'm slowly working through & summarizing 18th C wills + trying to sort out missing records (eg Lonan/marown marriages) so I might be able to look at the wills when I'm next in the manx Museum in a couple of weeks.