If it were mine - some questions I would be asking myself:
Would I have bought it - at a yard sale, at a thrift shop, at an antique shop?
How much sentimental value does this have for me or any other family member?
If the sentimental value is great, how much effort do I want (or can) put into it?
Are the usable blocks attractive? I've heard of people making pincushions of small blocks. Teddy bears. Or framed and made into pictures.
All the blocks scattered throughout the quilt?
Some fabrics do disintegrate over time. I think it's the equivalent of a car rusting out and turning into big orange flakes.
Maybe a fad can be started for "tattered quilts" similar to the "torn, faded, abraded" jeans that people wear.