There were a lot of entries missing in early civil registration of births and deaths in England. Until 1875 there was no penalty for failing to register a birth, and I suspect deaths were the same. Apparently until fines were introduced for non-compliance many people thought that the parish register record of baptism or burial was good enough.

For wills try the local CRO indexes, or if the assets were substantial see the PCY (York) indexes for the north, and PCC (Canterbury) for the rest of England and for people with property in both areas, or overseas. However England was not like the IOM with the number of wills left by "ordinary" people. They were usually left by people on limited incomes only if land was involved.

Sue