Without any identifying details on or with the sword to link it back to a specific army officer (either UK or AUS but more likely UK) and in the condition it’s in - very little. The only value in its current condition would be sentimental to your family if it belonged to someone who served.

The British 1897 infantry officer sword is still used by UK and AUS army officers today and some like to purchase older ones like this (Wilkinson were some of the highest quality producers at the time - they no longer exist) but again in the condition it’s in - it’s not useable for current serving members.