I looked through my 88's then some of the other years. On the ones with clear enough 8's, I found the same thing for 1883-7-9.
It looks to me like the 8 was repunched with a 3 punch. Looking at the 8's on 188-'s, they start off looking the same but some get fat, and the centre holes are different shapes. The ball on the top of a 3 would make the small semi-circle that's in the left 8, and the little ridge on the 8.
If someone has a program that can overlay a 3 from 1883 over an 8, it would helpful.