An exhaustive study of the Septuagint (LXX) showing the words from the Greek and Hebrew that translate into "elect" in the English bible had no such meaning for the translators of the LXX.
In a nutshell:
The deal is, the main book the 1st Christians used as their bible was initially the Septuagint (LXX) - the Greek version of the Hebrew Old Testament, as seen quoted by Jesus and the apostles in the New Testament - to this was added the letters and the gospels. All of these were books of scripture for Christians in Greek. It was not till the 4th century that translations into Latin began. The evidence from the LXX is that the only word from which "elect" comes from as read by these 1st Christians is EKLEKTOS.
And there, in the LXX, you read of the fat cows that came out of the Nile in Pharaoh's dream which Joseph interpreted as EKLEKTOS cows; The fat kernels of wheat were EKLEKTOS wheat; Young men - guys in their prime and thus the best to pick as soldiers - EKLEKTOS; pleasant land - EKLEKTOS land; highest branches - EKLEKTOS branches; choice silver - EKLEKTOS silver; With the pure thou wilt show thyself pure - EKLEKTOS . . . EKLEKTOS; And many more.
So, when the gospel writers quote Jesus saying "Many are called, few EKLEKTOS" it was natural for them to understand "few were up to it", "few were quality": "few have mettle". And also for all uses of EKLEKTOS the meaning of "excellent", "the best" as in view.