The memorial quilt I have made was made from denim and flannel shirts. I also added photos to the quilt, appliqueing them onto blocks. The quilt was from my husband's clothes, and made it for one of my sons. He was also 58 when he passed away.
I am not sure how I would use scarfs in a quilt, except they probably would have to be backed with something to make them not too stretchy. I think I would use a light weight non-woven interfacing, but maybe someone else would be able to give a definite recommendation.
However you make the quilt, it will mean a lot for the person you are making it for.