EMI 'thirteen and a half by eight' were elliptical speakers unpopular in the USA. Sound waves are round not elliptical! Made in England by KEF, rarer everywhere than hen's teeth, DECCA did a 'me too'in...
So you are selling an old radio, or you just bought one, and you want to know what year it was made? Well, there are some clues that you can use to determine the decade it is from, and then you can use that...