Hi all, I managed to find Neville's cardigan from Harry Potter and the Deathly Hallows: Part 2 about a week ago online and am currently stumped as to the shirt he wears underneath it. I have no thoughts on what to call this pattern and no recognition of the shirt's style. If anyone has any thoughts or feedback it would be highly appreciated. I have embedded a closeup of the shirt's pattern/motif for reference.
Thanks!

Thanks!