Sadly, there is nothing that can be done to strengthen old paper rolls.
When I worked at the National Maritime Museum I had long discussions with
the Paper Conservation Department.

Certainly, I always take the paper off spools with metal flanges. I clean
any corrosion off the flange, polish it smooth, and then protect it with
some wax polish and then buff it. The roll can then be re-attached to the
spool making sure it is close to the right-hand flange and is straight
and true.

Adding adhesive tape to the tattered edges is the only practical way to
reinforce damaged edges but this has drawbacks too. It thickens the edges
and can cause tracking problems. The only tape I ever use is Filmoplast P.
This is a very thin tape and does not seem to degrade over time. _Never_
use any form of plastic tape such as Scotch tape.

Over the last few months I have repaired several Duo-Art Pipe Organ rolls
which were damaged almost beyond hope. I had made a roll inspection jig to
take the rolls and the first task was to lay all the tears & folds flat.
I use a heated spatula for this. The roll is then carefully rewound onto
its spool making sure that all the paper is lying flat and correct.

The roll must then be left for a few weeks for the paper to relax back to
its correct state. The roll can then be wound through the inspection jig
once again using the Filmoplast tape on the outer surface of the paper.
Use the smallest size pieces of tape that will do the job efficiently.
Experience will let you know how much to use.

Happy repairing!

Richard Cole