What a great story, the perfect kind of HN post. Did Sinclair advertise in Greek... Or did your Grandma speak enough English to figure out what to buy?
I had seen advertisments in greek from the Greek importers of the brand. I had asked my mother for it and she delivered.
Since you asked for the greek market I can share one more memory. About a year later, 1982, I wanted to upgrade to Texas Instruments TI-99/4A so I tried to see a machine up close going to the local representative. I ended up at the "company's HQ" which was a small residence appartment in the fifth floor of a building.
I found the door open so I entered a room full with boxes thrown around randomely. After waiting alone for an awkward period of 5-10 minutes, the owner of the company himself emerges from the bathroom with a wet face and kind of surprised to see me. He listened to what I wanted. "It's somewhere there, go and have a look" it's all what he said. He couldn't care less.
13 years later I had my own small company and reselling PC and equimpent was part of the job. The man with the wet face was one of the biggest suppliers in Greece, since besides Texas Instruments he moved on to be the representative of Intel and Microsoft and reseller of many others and the company became on of the biggest in Greece.
Maybe his mentality ("there it is, go and have a look") never changed much though, because a couple decades later the company went bankrupt.