Brass terminals are hard to buy. But it is easy to build it by your own
Here is a small step by step tutorial.
Step 1: What You Need...
1 brass screw 3 mm / 30 mm
1 telephone jack or another piece of plastic that fits around one knurled head screw
1 brass washer 3mm
2 ring connectors
2 knurled head screws 3 mm
Step 2: Prepare the Ring Connectors
One ring connector is for the inner cabling of the device. The other one for connecting the devices outside.
Step 3: Solder the Wires to the Connectors
Step 4: Mantle and Mark the Wires
You can mantle the wires with a shoelace and mark it with colored yarn.
Step 5: Prepare the Insulater
The insulator part of the telephone jack needs to be a bit wider to fit over the knurled head screw.
Step 6: Ready to Mount
So everything is ready to mount the terminal into you case.
Step 7: The Cabling Inside
Here you can see the inner cabling.
Step 8: The Mounted Terminal.
Here you can see the complete terminal. The first knurled head screw fits into the insulater of the telephone jack.