Thanks guys. Luke, I too have a few pair of tops, one even has looney tune characters etched into it!! I would have to dig it out. When I got it I thought how silly for someone to do that to a t top, but thinking a bit further along it will make some nice period wall art.
Thanks Warren, I suspect that the area was a colour matched tape. I have seen a couple of low mile original cars in person and never think to look close at the tops.