You need to experiment at leisure beforehand if you’ve only one chance at the book….I’ve only used a bridge camera (Fuji s1500 on auto) for document scanning (eg at the National archives) and it’s incredible how tolerant it is with focusing, in fact the last time I was there I didn’t even bother to’ square up’ to the documents, shooting at about 20degrees off the vertical!….One problem I hit photographing a more important book was barrel distortion which is prevalent at the wide-angle end of a zoom (and hard to correct) so using a medium focal length if compatible with macro might be a good idea

I’d beware raising the spine of any book never mind one which is over 100yrs old, you will almost certainly damage it. Arrange some support for the book so when it’s open the binding is supported so that the book is in a vee shape. It’s not a good idea to have the book placed flat on a surface.

Make sure your f stop is in the middle of the range possible with your camera, this will give you good depth of field and reduce distortions. Put the camera on a macro setting if you have one. Experiment with white balance setting to get the right one. Ensure that you have ambient good light but not direct sunlight as this will damage the book. You shouldn’t need a tripod.

This method gives me good results at The National Archive, but then I only want to record not produce a work of art!

Regards