Kevin:
Thanks for posting the drawing. The mock-up I saw appears to have been the shorter-horned version. I actually think I like the longer horn better aesthetically. It's more graceful. The line of maple laminate peeking out from under the coco bolo on the horn adds nice definition to the horn's shape.
I too am concerned about balance, plus I really prefer a longer bass that brings the lower frets closer in to the center of my body, because having shorter fingers forces my wrist into an uncomfortable bend when I reach for the lower frets.
I struggled with which body shape would work best, plus I prefered to avoid the weight of a standard-size body. I wanted something that had the classic Alembic look (I'm an omega fan) but still addressed the other issues.
I considered several trade-offs, including a full-sized balance point or even a Rogue body. I even messed around with redrawing the horns on the small standard to add length (I had no luck envisioning a redesign of the 3/4 body - I'm definitely not destined for a guitar design career.).
When Mica showed me the picture of the mock-up you mentioned, I saw potential, but didn't like the top horn. If I understood you correctly, you selected the longer version shown in the drawing you posted.
The more I look at the picture of your bass, the more I like it. The longer top horn looks kind of elegant and seems like it balances nicely with the size of the offset between where the two horns join the neck. Mica said she thought the horn looked something like the Europa top horn. I think the picture of yours makes it look a little straighter.
Hybrid or not, I like it and am interested in having one made in coco bolo as well. I'm not sure about the peghead design yet (considering fan or something custom), but yours looks great.
Now - What would it look like with a point bottom? (Just kidding).
Enjoy.
Bill