have a look at this "half open 8"
https://en.numista.com/catalogue/pieces707.html

My question is, how is an open 8 looking?
Maybe the 8's upper part is supposed to have NO alloy filling it in? So would it just be a die error????
I have ALWAYS thought that mine was with a closed 8, see Mexican example below, but maybe it's the open 8 since NO extra alloy is in upper hole of the 8!!

It has obviously nothing to do with usual definition for open and closed like in this Mexican example:
Open

Closed

I think we will have to decide if f.ex. this kind of variants should be shown or not, since it's also die errors???

Thanks for your help