It's definitely an H Tuna. It's on the right-hand side to the rear and I really want to think there should be something to the left of it. There is no room to the right of it. There is a short horizontal mark on the right of the lower H leg and a short vertical line on the left of the H leg. I think those are just stamp tool-marks. I can't find any reference where any letter is stamped to the left of an H, only to the right...as in HI. I am thinking maybe there should have been an I to the right, but there is no room for it. I was also thinking this could be some post-war contract piece, but I have not found any reference on an "H" only marking.
I need to also correct the finish. I stated it was white, but it's parked.
I think I'll post over in another forum that I can attach a picture to.