Joseph:
In theory I guess the owner can claim it back but it would have to go to an another shul, not kept in a drawer but in most cases it stays with the original shul. I am from Brooklyn where neighborhoods change and so it’s rare that families go to the same shul generation after generation for almost a hundred years.
What I think happened is that years ago a grandfather donated a sefer torah, the children and or grand children have no relationship with the shul and don’t want to pay for the upkeep. The way I look at they are giving up their right the sefer to the shul. The Klaf can be whitened and a treatment to prevent the ink from drying and cracking can be applied that together with new etz chaims and a montale (Cloth Covering)and it will look like a new sefer at a lower cost.