OK, I managed to resolve this. And here is how i did it...

1. Exported all Notes into a csv file
2a. Opened the export file (File1) and created a row called Row Number, into which i then populated 1, 2, 3, etc. all the way to the last row of data. I then created another Column called Content and used a Concatonate formula to create an entry for each row using the string 'C:\Temp\Row ', the Row Number cell and finally '.txt'.  This resulted in a column with 'C:\Temp\Row 1.txt', 'C:\Temp\Row 2.txt', etc.
2b. I also created a Column called ShareType containing 'i' for every row (see developer notes to chose your prefered one, for some rows i had to use 'v' for viewer).
2c. Another column called Visibility and set every row to AllUsers (again, see developer notes to chose your prefered one)
3. I then saved the file (File1) and also saved a copy of the file (File2)
4. I opened File2 and and deleted all the columns except the one containing the Description, ie. the actual contents of the note.  I also deleted the first Row (of headers).
5. Saved the file (File2)
6. In File2, again, i created a VB script using some cool suggestions by other people online + a slight tweak of my own - Press Alt+F11, Click Tools, then Marco... and insert this in to the form:

' ******************************************************************************************************
Sub File_save()
Set Rng = Range(Range("A1"), Range("A" & Rows.Count).End(xlUp))
' for large files, if progream quits half way, edit A1 here to the next file required to continue.
For Each cell In Rng
Num = cell.Row
 
 Range("A" & Num).EntireRow.Copy
 Workbooks.Add
 ActiveSheet.Paste
 Application.CutCopyMode = False
 ActiveWorkbook.SaveAs Filename:="C:\Temp\Row " & Num & ".txt", _
 FileFormat:=xlTextPrinter, CreateBackup:=False
 ActiveWorkbook.Close True  'otherwise a excell window will remain open for each row!!!!
 
 ThisWorkbook.Activate
 Range("A" & Num).EntireRow.Select
Next
End Sub
' ******************************************************************************************************

7. I created the directory 'C:\Temp\', before running the script (click the green Play button)
8. For every row a file called Row n.txt was created in the Temp directory (where n is the number of the Row in File1, and this file contained the body of the note.
9. Now i imported the File1 into Note(ContentNote) using dataloader, mapping the Content field and the Title field.
10. Once imported, i used the success file to import into Content Document Link, mapping the ContentDocumentId to ID, LinkedEntityId to ParentID, Sharetype and Visibility

Now i had all the notes imported in to New Notes, but not without some glitches.  I found that some larger notes were trimmed to a single word (not good). I also found that i could not map the audit fields into the new Notes, although i have the permissions and the settings to do so.  So, in File1 i created a new column for the body of the note called New Body and used c combination of a User export file, VLookup and Concatonation to create a string to append to each note, which contained the audit info required.  it gave me something along this:

'Body of text, blah blah.

[Created by So-and So on 2016-11-11:21:00, Modified by So And-So on 2016-12-12:21:00]'

Anyways, although i couldn't find a fix for the missing/trimmed text in some of the notes i thought i'd post this as it might just help someone else and could lead to teh same or someone else finding the missing piece.
Enjoy!!

aamir