You might try putting the variegated threads or any that seem fragile to you in the freezer or in a bag with some moisture. Sometimes they dry out and can be revived. It's worth a try!
If you decide later on to use them, I have seen threads, trims, lace, scraps of fabric, etc laid on top of a backing piece of fabric, and then netting or some other very thin fabric put on top and then sewn over, so you are creating your own fabric/project. It can be really pretty and would make great place mats or mug rugs or such that you could also share with other family who might like the reminder of granny.