Thank you for the welcome.
The "Garnet" Japanese maple came from a nursery (Lakes Nursery) located in Auburn, CA. It had been raised there and the 2 main branches low on the trunk were already "twisted" and trained to go around each other. There was a "void" space in the middle of the twists that the nursery had placed a flat river stone and some juke/twine to hold the stone in place. After the 1st. Spring of growing in our yard, I removed the stone and the area has remained open between the twistings.
I removed it because I was worried, long term, the stone might damage the bark/cambium.
I have added a photo of the area on the trunk, below.
Here is a link to the nursery (I am not affiliated, etc.).
If you go to their Photo Gallery section, you can see photos of a large Japanese garden right in the middle of their commercial nursery. The current owner indicated the original owner had worked on the garden for 30-40 years. I think the garden is not trimmed/maintained as it was in the past with some over-growth allowed. Their Koi are extremely large and healthy, though. Pond is over 4-5 feet deep with vertical sides.http://www.lakesnursery.com/cms/index.php