Dear Mr. Hagedoorn,
My name is Luiza Dlugokecki. I live in Poland.
I am not sure I am relative of this soldier but I am sure that his name is wrong.
In Poland there is a name Fabian ( Gabian or Vibian is strange, foreign pronunciation)
There are 602 person with surname Dlugokecki in Poland, you have a chance to find some relatives.
Regards,
Luiza Długokęcka
Kosma