Thank you Graham for the reminder. Yes, you did post the code and it works perfectly as you showed. If you forgive me, I will post it again as it will avoid having to look back at it.

Here was your code:
Sub ReplaceFieldsV6()
'Graham Mayor - http://www.gmayor.com - Last updated - 25 Sep 2018
Dim oFld As Field, oNewFld As Field
Dim oRng As Range, oSeq As Range
    For Each oFld In ActiveDocument.Fields
        If oFld.Type = wdFieldSequence Then
            If InStr(1, oFld.Code, "Figure") > 0 Then
                oFld.Code.Text = Replace(oFld.Code.Text, oFld.Code.Text, "SEQ Figure \* ARABIC \s \* MERGEFORMAT")
                oFld.Update
                Set oRng = oFld.Code
                oRng.MoveStart wdCharacter, -1
                oRng.Collapse 1
                oRng.Text = "-"
                oRng.Collapse 1
                Set oNewFld = ActiveDocument.Fields.Add(Range:=oRng, _
                                                        Type:=wdFieldStyleRef, _
                                                        Text:="""GA Numbered Heading 1""" & " \s", _
                                                        PreserveFormatting:=False)
                oNewFld.Update
            End If
        End If
    Next oFld
    ActiveWindow.View.ShowFieldCodes = False
lbl_Exit:
    Set oFld = Nothing
    Set oNewFld = Nothing
    Set oRng = Nothing
    Exit Sub
End Sub
The problem arises that the following line of code now has the wrong style and needs to be changed to reflect the main heading style it is sitting under, e.g. Heading 1 or Heading 2 and so on.
Text:="""GA Numbered Heading 1""" & " \s",
This change is being forced upon me as I'm quite happy to keep the existing one.

This code identifies the necessary heading:

                With Selection
                    Set figRng = .Range
                    Set figRng = figRng.GoTo(What:=wdGoToBookmark, Name:="\HeadingLevel")
                    figLvl = Right(figRng.Paragraphs.First.Style, 1)
                End With
Now the new line of code has to look like this:
Text:="""Heading " & figLvl & """ \s"
THIS is where the problem arises and I'm trying to figure out a way to accomplish this change.

Again, I reiterate my "thank you" to you, Graham, for your help. I would not have changed the code if it had not been foisted on me to do so.

Roderick