My version will also be oak but some pine boards found on the roadside will serve for a practice version.
Upside down close up of the bottom showing the bottom fitting into dadoes and grooves. The original Viking chest used dadoes on the ends and a rabbet down the sides.
The oak version will have angled sides but I just made straight sides on the pine chest. Here you can see the end pieces.
The top is on the right.
A dry assembly test fit. Looks good to go.
Part 2 will be wood hinges, assembly and finishing.