Runic script is worth getting to know.  It was used by Germanic
and Scandinavian scribes before they adopted the alphabet,
based on the Latin script we use today.

Some early Anglo-Saxon coins exhibit runes, often mixed
with English script.

An understanding of hallmarks is very useful in determining the date
of metal detected gold and silver items.  Dating jewellery etc for
friends and family is also appreciated.

Learning to read hallmarks is not difficult with a bit of practice, and
there are plenty of reasonably priced books available.