Great job! T-shirt quilts are a real challenge anyway you look at it. I have done a few but only because they were commissioned. Not something I would do for myself! The printed parts are always different sizes and enough to drive you crazy. You've really done a super job with his shirts. Your friend will be thrilled with the results.
( Just a thought for you - in case you find yourself doing another.... I have always found that horizontal sashing helps out in making it all come together. This is NOT a negative comment on what you have done! Being able to make rows and then sew the rows together has worked for me. )