Harry, I'm sure Joseph will see this and reply at some point, but afaik his work on flowers makes the distinction between a closed anther cone, vs one in which the stigma is exerted. Looking at your picture of the open flower on the left, you can see that the stigma is 'exerted' ie it sticks out further than the anther cone. you can also see that the anthers are curling back at the end instead of forming a tight or closed cone. So I think you have the right phenotype for "Big Hill", with open anthers.
I'm loving to see your pictures of this cross which is very interesting to me! and hoping to grow it in future. Please keep posting your pics!
I can see you have some fruit setting already (those finished flowers are really "closed"! and around some baby fruit I'd say.)
