I, of course, am referring not the King himself but to the KJV.
My big beef with King James translation is "most favored one" for "kecharitomene" in Luke 1 and "elder for "presbyteros". Both are highly questionable and just happen to obfuscate the two significant elements of Catholicism. Yes, NIV is pretty bad.
Regarding "presbyteros", like you mention later, the word "priest" derives from it, and functionally the references are to Christian priests at least in some contexts; certainly in 1 Timothy 4:14 where the reference is to Timothy's ordination.
It is true that in a vacuum "elder" would be a good translation. But KJV does not exist in a vacuum. Then and now, Christian churches have priests; till the Reformation it would not occur to anyone to translate it as "elder". It is as if someone wanted to erase the references to the "president" in the US constitution and started referring to that word as "chairman" instead, or perhaps "front-sitter". While "president" derives from "chair" or from "to sit in front", it has an established meaning that is all-important in American politics.
Uh, til the reformation, there wasn't a word for elder.
However, I do beg to differ on the translation. Presbuteros is used for an older person. Old man. Old woman. So, ELDER, is the natural translation. It isn't questionable to translated it as Elder. Nor, knowing the origin of the word Priest can that be 100% ruled out. However, it isn't likely that the best meaning is Priest since the KJV and others refer to priests frequently in the OT and NT, and a different word is used to describe them. High priests. A kingdom of Priests. ect., Different word.