Is the sleeve glued to the back of the quilt? Or just to itself? If it is glued to the back of the quilt, maybe you could just leave it as is and use the glued together area as the fastener, rather than sewing it too. Or is the glue on the back of the quilt and not the sleeve? If that is the case, can you make a slightly larger sleeve and cover the whole glued area and stitch it down as originally planned? If it is only on the sleeve, can you toss it and make a new one?
If it is extra strong multi purpose glue, I don't think its going to wash out.