The pictured T-20 transmission is for sale.
It has not been used by since since purchased used here in the 6x6 forum from thebuggyman1 several years ago.
It has been stored in a climate-controlled area - the building seen in the pictures.
There are no known issues. It seems to function by hand by turning the diamond gear shifters, applying and releasing the band brakes with the popsicle sticks, and turning the input gear while observing the output gears.
I am not too current of the T_20 market these days - I think I am about to name a lower-than-normal price, but if I am off-base, feel free to show me other examples.
The price for this T-20 is $500 for local pick-up in northern Phoenix/Glendale.