[EDIT: I'm too late to edit my previous post about Durham Records Online, and Gadget has already looked there now anyway (see next post), but there's something else you might want to consider, as follows:]
As you already have an image of the BT, the most useful extra thing the PR is likely to offer you would be the original signatures, which you wouldn't get in a transcript. From a quick look at Genuki, it looks as though the registers can be consulted at both Northumberland Archives and Tyne & Wear Archives - obviously one of these will have only a filmed copy, but even where an original register is held, you are usually expected to use a film.
According to their websites, both these archives have a copying service, but I don't know what it would cost. Others who use these archives regularly might be able to tell you more.
