Can you identify this Crown accordion?

[Britt]

This Accordion has been in my family for a long time. Unfortunately, my grandfather was the last family member with an interest in playing it and I am trying to identify it and see if I can find a buyer for it. A local music shop told me that it is somewhat unique.

If there are other photos that would help, I can easily take them. Thanks in advance for any help you could provide.

I'm near Chicago if anyone is interested in it and can offer a fair price for it.