I bought my JD 2030 used without a loader. I looked three years for a loader. Then it was missing mounting brackets, (not the main mounts) hardware and hydraulic fittings to attach. I was lucky it had the valve, joystick and cables. I had to buy the mounting bracket for the joystick too.
I bought all the parts from the JD dealer at about 5x what I had guessed when I bought the loader. It can be done, but it takes time & $$$, and labor to install. You also have to make sure the valve is compatible with your hydraulics, open center verses closed center. JD made both, some even in the same model number, mid year
change.
I second buying with a loader, much easier.