About half of a 5 litre bottle of specialist woodworm treatment that did the trick for us a few years ago & now no longer needed (famous last words!)
Unfortunately the labels have worn off but it's just a case of brushing on to the affected items & allowing to dry.
Hopefully someone can make use of it.
Woodworm treatment (Bowbridge GL5)
This offer has been gifted to someone and is no longer available.