Bretts, Thanks for sharing this with us. Hornbeam probably is one of my favorite of the deciduous trees. The following is my two cents worth.
....from a stylistic viewpoint,I'd make those scars front and center.You can have a nice tree that looks similiar to so many others or you can have one with character from the get go.Very nice material!
andy
I agree with Andy! The massive scaring needs to be incorporated in the design. You can't hide it. If you put it to the back you will fuel the opinion of the naysayers. I think that some creative carving that pulls all the scars together in a series of "peek a boos" connected by a hollow/crevasse in the main shari could be convincing and give unique character to this tree. You may, if your lucky, resolve some of the reverse taper with the carving as well.
I would make one prediction of gloom and doom by saying that the vein (1st pic lower right hand corner) between the two scars will probably not make it and will die off. It has been my experience that hornbeam usually abandon thin ribbons like this and focus their energies to the rest of the tree. So be prepared to have that shari increase.
You might want to consider next time leaving a stub instead of flush cutting. This will give you a few more options. The first would be a hollowed out branch that would lend itself to the rest of the tree and its proposed theme. Flush cuts and carving are very hard to pull off convincingly. The second benefit by leaving that lower branch is that the vein might survive by virtue of the remaining branch collar.
It took me a very long time to stop myself from wanting to flush cut. I eventually learned that by leaving stubs instead of rushing to a final trunk image that I opened another door visually and horticulturally.
I like your tree and wish you the best of luck with it. Please keep us updated in the future.
EDIT: I forgot to add, check out
http://www.kaizenbonsai.com/gallery.htm Graham Potter has some excellent examples of deciduous carving on his site. Might give you some ideas. It did for me