Hi - Thanks for listing the missing Epis indexes.
I think your URL should be:
www.isle-of-man.com/manxnotebook/famhist/willsums/epiwills/index.htm
Regarding your "solitary new index to an archideaconal film - RB516 that covers 1655 - 1662", that doesn't coincide with the LDS film dates. Interesting - I always thought that the MM had the same films but with different call numbers.
Arch wills 1660-1664 are on FHL film no.0106200, and the previous film [0106199] covers 1655-1659, which is the latest one which Joyce has indexed.
Sue