well i think Ethiopia is more likely than Ireland..
even so:
In those days, when your numbers have increased greatly in the land," declares the LORD, "people will no longer say, 'The ark of the covenant of the LORD.' It will never enter their minds or be remembered; it will not be missed, nor will another one be made.
(Jeremiah 3:16)
because, just as you say, the true ark is in heaven, and we have Christ - there is no need of the 'shadows of things to come' for us.
Christ is not the shadow of the Ark though. The Ark is the Mercy Seat, the very Throne of God. That Throne will come to the earth...
Rev 21:1 Now I saw a new heaven and a new earth, for the first heaven and the first earth had passed away. Also there was no more sea.
Rev 21:2 Then I, John, saw the holy city, New Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband.
Rev 21:3 And I heard a loud voice from heaven saying, "Behold, the tabernacle of God is with men, and He will dwell with them, and they shall be His people. God Himself will be with them and be their God.
Rev 21:4 And God will wipe away every tear from their eyes; there shall be no more death, nor sorrow, nor crying. There shall be no more pain, for the former things have passed away."
As far as Ireland, Jeremiah and Baruch transported the princess Tea-Tephi there. Tea-Tephi was the daughter of (and only survivor of) King Zedekiah. All of his sons were killed and if this part of the Word of God is to be true...
Jer 33:17 "For thus says the LORD: 'David shall never lack a man to sit on the throne of the house of Israel;
Jer 33:18 nor shall the priests, the Levites, lack a man to offer burnt offerings before Me, to kindle grain offerings, and to sacrifice continually.' "
Jer 33:19 And the word of the LORD came to Jeremiah, saying,
Jer 33:20 "Thus says the LORD: 'If you can break My covenant with the day and My covenant with the night, so that there will not be day and night in their season,
Jer 33:21 then My covenant may also be broken with David My servant, so that he shall not have a son to reign on his throne, and with the Levites, the priests, My ministers.
Then someone of the royal family had to survive and that was Tea-Tephi. No one knows exactly where the Ark is, but Ireland is as good a guess as any. Do a search on Tea-Tephi Ireland and see what you might read.