Reply To: Find/Change only on Master Page?

No… but you can do it easily if you have used Layers.

There IS an “include master pages” button in the scope section of Find/Change. So turn that on to find stuff on the master pages.

So put all these master page footers/headers on a layer (where they should be anyway). Then when you do the find/change, Hide all the layers except for that header/footer layer. By default, InDesign won’t find text on a hidden layer.