The TR-77 went on sale in the spring of 1958 as the export-only sibling of the TR-67. This makes it one of the first models to ship after the company name was changed to Sony Corporation in January of the same year. Obvious design differences when compared to the TR-67 include the brass carrying strap stays added to the sides, the ALL TRANSISTOR lettering molded into the upper front, as well as the big number "7" and horizontal line pattern added to the gold "V" flash. Also note that Sony chose to use a different plastic for this "UNBREAKABLE CASE".
There is a grave lack of documentation on models not sold here in Japan,. But near as I can tell, the production volume was extremely small, with just a few thousand units sold primarily in Canada and Germany. The lineup included three colours (mandarin) red, beige and black.