The chinscales are held together with a bolt instead of the normal fastener at the front. This is not all that uncommon. The rosettes are not proper for this M1871 helmet as Brian mentioned. It should have screw posts instead of rosettes. This would be an easy change and you can find original screw posts, though it may require a wait.
My biggest concern is the Wappen. I'm looking at small photos so take this with a grain of salt, but there appear to be bubbles on the Wappen surface especially around the bandeaux. Take a close look at a blown up section of the Wappen that shows "F. FUERST" and you will see what I'm talking about. If I were looking at this helmet I would request a photo of the reverse side of the Wappen. If the seller refused to remove the Wappen, which is his right of course, I would ask for additional close up photos of the wings and the bandeaux.
I would definitely bid at it's current price, but I wouldn't go too high unless I got better info on the Wappen.
Just my opinion.
John