Sorry to hear that. I also had a co-worker that painted skulls that were amazing from the Ponca Tribe.She died back in 2020 from COVID
I think her name was Lois Red Feather.
He took his 4 week vacation in January of every year. Built a sweat lodge behind his home that was basically a hovel. He would take the bison skulls into the sweat lodge, Do peyote which is legal for that tribe, and paint.
After a month of shrooms, fasting, and sweating, he would come to work and never miss a day for the rest of the year.
The skulls he painted were absolute works of Native American art. He got thousands for each.
One I saw was of the tired worrier on a horse with a spear in hand at nighttime with stars in the background.
It was so real you thought you were looking at it with your own eyes. The depth perception was perfect.
RIP Oscar.