Not sure how seeing the bigger picture would help, but it's moot; not enough room to maneuver for better pics.
What are the "three or four common thread sizes"?
The place was built in 2016, if that helps...
I am tapping into my toilet's water supply line to provide water to a bidet toilet-seat.
The 1/2 in. fittings supplied with the bidet would work on the fittings inside my toilet... but I can't reach them. The toilet is installed too close to the wall.
But the valve at the wall is accessible...