Old Walnut? Chest

This chest has been in the family for a long time. It is dark wood - maybe walnut?

I need advice on restoring it. Top has water spots. Inside looks like new, maybe cedar lined. I have used Formby's refinisher before on other pieces with good results, although probably ruined values. I won't do anything to this without good advice.

I am also very interested in opinions about its origin and value. Thank you.