To repair? restore? rebind?

I have this one   should I restore it as far as possible to original to make it look like its original, or put on a complete new binding , correcting the structural issues, so it can  be read and used not just look like its original? Lots of cost difference between the two.  A discussion below.  Jim

 

Fine Binding In America  1956

“After all that can be said in favour of retaining books in their original covers, there are very many which for their preservation demand rebinding, even as old rags should give place to proper clothing. Every collector, if he takes a just view of the matter, cannot do otherwise than consider himself as their temporary custodian, and wish to transmit them to his successors if possible in better condition than when he acquired them. Perhaps some critics may still cavil at what they consider a too lavish expenditure, and still vaunt the superiority of the "original cover." If these are good, any renewal of them is unnecessary, but as all books must have bindings, it is surely better to have them well done and even elaborately decorated, no matter when their covers may be placed upon them. The better they are, the better the chance of the survival of the volumes, and the best will wear out soon enough.”