T-shirt sizes are somewhat puzzling. Depending on brand I might be an M or an L. I am built as I was 25 years ago yet the size of some of my Maiden T-shirts from back then is XL!
I agree with
@AncientMariner_Essex about metal T-shirts. These days I favour subtle designs instead of “the zombie will gore you” ones. I have been selling a good number of Maiden T-shirts on ebay for that reason: I’d rather see a collector enjoying them that having them in a drawer at home. That being said, I am keeping some I am more strongly attached to (Powerslave, Live After Death and my first Maiden T-shirt, Fear of the Dark bought at HMV in Oxford Street back in 1992).
For what is worth, I like that Wicker Man T-shirt!