I am confident in asserting that it comes from a can of Ecco Tomato Juice, as all three recipes on said label call for the use of that product.
But what was Ecco? I can't find much.
In addition to Ecco Tomato Juice, there was also Ecco Grapefruit Juice and Ecco Cocoa. I found advertisements for the juice products in 1941 issues of The Sun of Lowell, Massachusetts.
My best guess is that Ecco might have been the "store brand" of Economy Grocery Stores Company, a New England chain of supermarkets that was founded in 1914 and changed its name to Stop & Shop in 1947. The dates and regions seem to correlate with the scant evidence I have, and the Economy Grocery/Ecco link seems reasonable.
The three recipes on this Ecco label are for Surprise Tomato Cocktail (secret ingredients: pea juice and allspice), Tomato Juice Cocktail and Tomato Twinkle.
The Tomato Twinkle recipe is disturbing. It seems to creep into that territory that I explored last October in the "Things you shouldn't put in Jell-O" post.
1 tablespoon plain, unflavored gelatine
¼ cup cold water
1¾ cups Ecco Tomato Juice
1 teaspoon Worcestershire sauce
¼ teaspoon salt
⅛ teaspoon pepper
2 tablespoons lemon juice
¼ teaspoon grated onion
¼ cup stuffed olives, sliced
Soak gelatin in water 5 minutes. Heat tomato juice to boiling point. Add gelatin and stir until dissolved. Add Worcestershire sauce, salt, pepper, lemon juice and onion. Chill until mixture beings to thicken. Put a thin layer in the bottom of wet molds. Arrange layer of sliced olives over the bottom. Fill with tomato mixture. Chill until firm. Unmold and serve on lettuce with mayonnaise. Serves 6.