Hard to say on the British Tan, here is the creed patch:The strap on the black one looks like a replacement. I don't have any photos of the Basic Bag sides or strap mounts but the rest of the bag isn't showing any red flags. What year was the tan one made?
My original thought was that they had replaced the strap as well, but the details on the side are so different. The metal rings on the side of the black bag are significantly smaller and thinner than the rings on the British Tan one.