RCA RTU7877 TV Manual
Found this low cost RCA RTU7877 78 inch 4K UHD TV for less than $1000, but didn't see a manual online for it, so I scanned it in for anyone who might be searching for it.
By the way, you can access the service menu by hitting MENU on the remote, then pushing digits 1-1-4-7. This will let you access additional settings. I have also not found a way to turn off the "fluid motion"/"motion interpolation" on this TV, unfortunately.