So we know from the T-shirt, if it's WOJ, that McAnnaly's Pub opened 1994.
Looking at that 2nd symbol, it is either Mjolnir or Labrys.
So, Peace and then a symbol of war.
It may, if Jim had a hand in creating the T-shirt, be a hint as to Mac's identity.
If the second symbol is Mjolnir, then it is likely he may be Thor or someone associated with it, his descendants.
If the second symbol is Labrys, then we need to research who identifies with it.
https://en.wikipedia.org/wiki/LabrysIn the Near East and other parts of the region, eventually, axes of this sort are often wielded by male divinities and appear to become symbols of the thunderbolt,[9] a symbol often found associated with the axe symbol. In Labraunda of Caria the double-axe accompanies the storm-god Zeus Labraundos. Similar symbols have been found on plates of Linear pottery culture in Romania.[10] The double-axe is associated with the Hurrian god of sky and storm Teshub. His Hittite and Luwian name was Tarhun.[11] Both are depicted holding a triple thunderbolt in one hand, and a double axe in the other hand.[12] Similarly, Zeus throws his Keravnos to bring storm. The labrys, or pelekys, is the double axe Zeus uses to invoke storm, and the relative modern Greek word for lightning is star-axe (ἀστροπελέκι astropeleki)[13] The worship of it was kept up in the Greek island of Tenedos and in several cities in the south-west of former Hellenic Asia Minor, and it appears in later historical times in the cult of the thunder god of Asia Minor (Zeus Labrayndeus).
Based off that, the Labrys are often wielded by gods associated with thunder, storm, lightening etc.
The first symbol though is undoubtedly of Norse origin though there may be other cultures where it exists and represents peace too.
