Found Old Saving Certificates Ninth Issue?

Hi,

We bought an old house and when we were renovating we found five 100 pound saving certificates (ninth issue). The stamp on three of them is 1979 and the other two are 1980.
Just wondering who would we contact about these? Does anyone have any idea how much they would be worth?
The man that lived here is dead and as far as I know none of his family are living locally?

An Post deal with Savings Certs.

Give them to his family or get them to sort it.