For what it's worth, my identical Nikon F2, purchased by me in the mid-1970s, also managed to get its titanium shutter curtain creased right after I purchased it. (Not by me, by someone else!) That was almost 40 years ago. It still works fine today. Four decades of firings have smoothed out that crease considerably. But if I look close I can still see it. It's never been a problem for me in all those years.