While working the Wildcat at Hershey last night, I saw a guest with a B&M shirt! It was plain white and had "B&M" written across the front in big, blue letters. Below that, it had "World Class Coasters" written. "B&M" was also written in small lettering on the sleeves near the shoulder. The back was plain. He also had a hat on. Dark blue and had "B&M" written across the front in white lettering.
I wish I could've asked him where he'd got it, but I was operating at the time and couldn't leave the control panel. =(