King James II Crown Or Half Crown?

Hi!

I'm new here. I inherrited my Gandpas old collection of random coins recently and have been starting to work out what they are, whats fake etc. There's a couple I'm still not too sure about so I was wondering if you guys can help?

The one bothering me the most is the James ii half crown or crown thing. I've reduced Google to a shuddering husk looking for an answer.

How do you tell wether it's crown or half crown? From the images on the web both are identical. No one mentions variations in marking or diameter. If you know what my coin is then please tell me. I'm guessing that it's a half crown because the size matches my Charles II halfcrown.

Anyway here's the scans;





Cheers :)