I believe this vintage Shell Oil can dates to the 1970s, it's a 5 quart can, and Shell Oil started transitioning from the 5 quart cans during this time.  The style of the Shell logo also dates from this era.  
 
The Shell collectibles are very hard to find, and this one is in really nice condition in our opinion!
 
Measurements:
9.5 inches tall
7 inches wide