If the problem is that the chest is too big, this can often be fixed by putting a dart on each side, in the inside “corner” where the neckline changes direction from parallel to the ground to at a right angle to the ground. If possible, it would be best if you could pin the 2 darts in place, to ensure that the blanket repair people know exactly where to put the dart, and this will also help to confirm that the angle of the neckline is the problem. Putting in these 2 darts does no so much make the chest area small, as left it higher and change the angle. This is relatively easy for a good blanket repair place to do if the T/O is a light weight or a medium weight. It often does not work with heavy weight blankets, as there is just too much thickness for the darts to sit flat to the blanket.