I believe the incident at Hal Far/Luga happened in the early 70's. The airfields are not far apart, and HF was used as a relief landing ground by the RAF.
It was the German operator's first flight to Malta, and he landed successfully and then asked for taxiing instructions. The Luqa tower was somewhat mystified, as they couldn't see him , and had to ask him his position. A question & answer session then followed until they established that he was a couple of miles short.
There was another airfield near Luqa, called Ta'qali I think, and ISTR that there had been some similar incidents there as well. Ta'qali was completely closed and unusable by the 70's.