Well, after planning on doing this cosplay for over two years... I've actually done something towards it. Hurrah!
It should have been way easier to find a shirt like this... and it should have been way easier to MAKE a shirt like this once I discovered I had to resort to the actually-sitting-behind-the-sewing-machine-route. But I'm not that great behind said sewing machine so it took a lot more effort than it looks... but two ruined shirts later, it's done. And that's what counts.