Thanks eveyone. You've all been helpful.
The reason for my interest is that I've been listening to Dr. Morecraft's seminar on the Westminster Standards.
Also, a quote from him in an article explaining why the RPCUS uses the original confession:
The state is to take order for those objects at which it aims. This expression is a technical one, common in the theological debates of the Westminster Assembly. It means “to provide for, to attend to, to take care to accomplish,” language far from implying the usurpation of authority over the church by the state. The Scriptural footnotes of the original chapter 23:3 supportive of this duty are Isaiah 49:23, Psalm 122:9, Ezra 7:23-28, Leviticus 24:16, Deuteronomy 13:5,6,12, II Kings 18:4, II Chronicles 34:33, II Chronicles 15:12,13, which footnotes show the theonomic perspective of the Westminster divines. Because of their Biblical hermeneutic, they could, without hesitation or apology, quote Old Testament laws and examples for the state today, believing as they did that the Hebrew Republic was in many ways a model for nations today .4 As Greg Bahnsen pointed out: “the Mosaic law is a `model’ to be emulated, not a code to be simply quoted or read into modern statute books.”- NO OTHER STANDARD, p. 160.