From the late 1800s through the 1930s there were a lot of spectacular Bibles sold throughout the country. They were often sold through subscription. People were buying a family heirloom Bibles, and impressive ones at that.
They were substantial in size, often three or four inches thick. The covers were imbossed with interesting patterns filled with lots of gold applied to the covers and spine. People weren't just buying Bibles, the were buying treasures.
Unfortunately, they were buying books which were substantial in size and decoration, that unfortunately had no substance to the binding or construction.
They were poorly made, with bindings that could not support the weight of the textblock. The paper, typical of the time, was very acidic and soon turned brittle.
However they can be repaired!
The only way to fix these bindings is to take the covers off and reattach them in a much more durable manner, by inserting a cloth hinge inside the cover boards and using that to attach the covers to the book.
After that is taken care of, a new covering material (either leather or lined Japanese paper) can be placed under the original cover to camaflouge the repair. The original spine is then replaced on the book after the damaged pages are repair and the spine of the textblock is treated.
The result is a repair which resues as much of the original cover and spine as are existent. And a repair which will last many more generations!
The acidic, brittle paper can also be deacidified. Though it is an expensive process to treat all the pages of a Bible made of acidific paper, deacidifying a few pages, such as the birth and marriage records, can be done for a reasonable amount.
In the end you'll have a Bible which will be passed on to your great-grandchildren.
It will finally be the heirloom you ancestors thought they were buying a hundred years ago!