Brake Proportioning Valve issues

[WIDESIDE72]

The shop that painted my dad' truck lost the master cylinder to frame lines. I bought a set from inline tube and I went to install them today. I installed the mc to prop valve lines and line that comes out of the bottom of the prop valve with no issues, but I have run into an issue with the line that goes into the rear of the prop valve. The hole in the valve is around 3/4 to 1", but the line is just 3/8". I have another prop valve but it's a little different and it just has a 3/8" port that the brake line will thread in to. I wonder if they took the line out of the valve and lost more than the line, such as an adapter (?) It figures that they painted the prop valve body color like they did the mc and power booster, but if I can't install the line I'll have to pull it clean the other one I have paint it black and install it...

Does anyone have any idea what happened with the prop valve?
Posted via Mobile Device
Posted via Mobile Device