What a pleasant surprise to find! Have fun finishing those 15 quilts. You could always start cutting out your new quilt and work on it in between finishing the others.
I think you should reward yourself for the UFO's you have finished.Those new found ones will just have to wait a bit longer besides they "'snuck'' up on you -unfair behavior on their part
wow what a find i keep looking but cant find any undone here..lol.. i guess you have to make them first huh?
well i am happy for you and that makes christmas much easier...