you can slip some fusable webbing inside of the patches where they are coming apart, carefully put them into place then press. after you have fused all of the areas together set your machine up and quilt the squares, either in the ditch or 1/4" inside each patch would work well to hold everything again. i am assuming the backing is ok? i have repaired a number of quilts for people that i really thought should just be tossed but they wanted to keep them and still use them. i found using the fusable first too get everything together then stitching works well. if there are any areas that you can not put it together good enough you can applique something over those areas. using a fabric that compliments the quilt, or carefully remove the bad patch and replace it. it is a very do-able project.