Could always make the quilt yourself, it's not that hard to make a simple one with big blocks from the shirts.
T-shirts already have a front and back. You just need some long running stitches to join two shirts together. Shove them with the amount of batting you want, and then another running stitch to seal them up.
Hand sewing a quilt is a big effort. If you love doing it, it's awesome. If you don't, it's just massively frustrating and time consuming.
I say this as somebody who hates all parts of sewing except old machines.