Al,
I thought you had all of this straight. I had to re-read through the entire thread. Here is what I think has been said.
We learned that one battalion of the 131st FA, 36th Texas Infantry Division was picked to go to the Philippines, where they fought bravely and were captured.
Then it was noted that the 141st Infantry Regiment, 36th Division, was the unit that became the Lost Battalion of WW2. (not to be confused with the lost battalion of WW1).
The 131st was Lost in the South Pacific in 1942. The Infantry Bn. was lost while a part of the 36th. in 1944.
This was your comment that summed up these two historical events.
The 131st FA still served with the 36th Infantry Division during it campaigns in Italy and later in France. It was probably assigned to support the 141st Infantry Regiment in the Vosges which is where Porter was killed in action.
Does that clarify anything? If not, repeat the question.
Steve