Hello! I have an ancestor, Eugene S. Lee, who was in Company D of the 14th Vermont Infantry! He was wounded on July 3, 1863.
The 14th Vermont did travel to Gettysburg for reunions. I have not found any photographs, but I think you will like this book,
A Short History of the 14th Vermont Reg't. (here), which also includes an account of their reunion on July 4, 1887. Of note, the book also includes a roster of members that were present at that reunion.
A photo of their curated regimental colors is found
here.
Charlie