If I could figure out how to post photos here and remember how I did it....
These are somewhat odd.
Upside-down, fat "T", so the horizontal fits A) on top of the console and B) under the seat bottoms.
The vertical part of the upside-down "T" is narrow enough to fit between the seat bottoms, then mushrooms out to fit over the top of the seat bottoms.
Stays in place that way.
I have photos, could build one, the upholstery looks to be the simplest bit, getting all the angles and lengths righ on the structure might take a bit.