Inherited family treasure

[Spanner]

My dad has had this since he was 11. That was as a boy in Holland in 1945. It was that one thing I looked at as a family treasure. Lots of mixed info that I have found and trying to figure out a manufactured time would be nice. My 1st WWII firearm but I hunt deer with an Eddystone Model 1917. I love and respect these old weapons. But firing it isn't necessary either. Was considering having it inspected by my gunsmith and taking it to the range if possible. I've included a picture of the spare magazine and what I believe to be the cartridges that were in the magazine when he got it. This was April 1945. He used to keep it wrapped up in a cloth but at some time in the last 25 years he got a P38 holster I didn't realize he had been storing it in.