Greetings,
Being a pipe maker myself for 30-some years, I am in no way an expert, as I'm always learning something new with each pipe I make. One thing I've have learned is, don't be afraid to remove enough wood to refine the shape.
I realize you probably paid a substantial sum for your block of briar (the grain shows it), but don't fall into the trap of "getting your money's worth" by preserving as much wood as possible. This will result in a "clunky", overly large and heavy pipe. Accept the fact that 50% or more of the block will most likely be scrap.
What I see in your photos is a good start suggesting a basic shape. Keep going. Slowly remove wood to reveal a more delicate, graceful, organic shape. Sometimes I'll set a pipe aside for several weeks, not even looking at it. Then I'll view it with a fresh perspective. I will invariably see something that can be improved, an angle or curve that I didn't see before. There always seems to be more wood to remove to sharpen and define the shape.
I've even re-shaped and re-finished pipes I've smoked for some time. After a while I see where it can be improved, and back to the bench it goes. I have a few pipes I've re-done 3 times! Such is the pursuit of perfection.
Study the pipes made by the "masters" - Rad Davis, Will Purdy, Bruce Weaver, to name three. Also, look at some of the Russian carvers work. Look closely at their creations. Notice what's there, and what's NOT there. See how much wood remains and what they take away.
I hope I didn't offend. Just trying to help.
Keep going and always strive to improve. We should never stop learning.
CACooper