I made an account specifically to reply to this. I found the post when I googled the 1275th Combat Engineer Battalion. My grandfather, Sydney Ross, was a Private First Class in Company C of that unit. I know for sure that he served in France and Germany in the spring and summer of 1945, and then in the Phillippines in the fall and winter of that year. We have a photo album of pictures he took during his service, but due to an unfortunate family estrangement, we don't have access to his original discharge papers (which I'm trying to get a copy of now), and his collection of flags and personal weapons from both the German and Japanese armies. I thought you might be interested in these links, which I found when researching the unit.
The first is a Google Books copy of an autobiography of a jazz musician who was part of that unit. This is cool because he specifically mentions towns which match the names written on my grandfather's collection of photographs.
The second is an operations log from a particular LST (LST 493) transporting troops from England to France, which happens to mention Comapny C of the 1275th Engineers, so I know the exact date of my grandfather's arrival in France (April 9th, 1945).
I'd love to know if you have any other information on the unit's movements and activities, or just any other random tidbits you'd like to share.