Hi Binge
My own Feest/Feast/Fiest research centres on Upper Beeding, seems to be a hot spot for this name and not too far from yours. Give me a toot if you find a link up.
I have my own parish map which is colour coded with IGI coverage and the area in East Sussex close to Falmer is poorly covered by the IGI. Best coverage is Stanmer, Westmeston, Streat, Kingston, Rottingdean and Brighton.
Falmer and a whole bunch of neighboring parishes are poorly covered.
The BIVRI has two Mary's
FHL Film 1068992
8 Apr 1739 Sompting
Mary Feast to James and Ann
FHL Film 1068527
13 Oct 1739 Steyning
Mary Feast to James and Mary