We can replace the tube for you. You can contact firstname.lastname@example.org
with a link to this message.
Unfortunately, w we don't have PLCC sockets for individual sale. The links in the parts list will take you to our sources for these.
Not sure what is up with the fuse. It should break the connection when it overloads, then recover again when it cools down. What resistance do you measure across the leads of the fuse?