Does anyone know what hat/helmet size Frank Thomas wore throughout his career? I have seen a GU hat sold on auction through Lelands at size 7, but I'm not sure who authenticated it. I have a GU Rawlings Batting Helmet size 7 1/8 authenticated by John Taube (GU) and PSA/DNA (Auto).

I took a gamble and bought what looks to be a legit Thomas signed GU ABC Batting Helmet size 7 1/4 that looks very legit to me, but I am hoping some Thomas collectors could provide some insight. Was there a difference in measurements between Rawlings and ABC? Did players helmet size ever fluctuate, and if so is this something seen with Frank Thomas?

Thanks in advance!