This is a unique, very good-looking vintage backpack by Barbour with the British Union Jack design theme.  It has a cinch top opening with rain cover flap.  There are two front pockets with buckle closures and two webbing pockets as well.  

It come with canvas adjustable shoulder straps and a stout leather carry handle.

Interior lining is all intact.  There are no interior pockets.

The only "flaw" is it is missing the leather buckle/tang with quick-detach magnet for the main fold-over flap, but with some sleuthing a replacement probably can be found on-line.  You can decern what is missing in the next to last photo.

Base to opening: 16"
Base width:  12"
Base depth:  6" 

Light wear.