Lord and God are two different words in the Greek.
Kurios does not translate as *God*.
Of course. I've already said that.
But Kyrios is used as a substitute for God. In the Septuagint, the Old Testament version commonly used during the time of Christ, the Hebrew name for God, YHWH, is Kyrios - Lord. The Old Testament verses I posted are evidence of that. Look them up in the Greek and you'll see.