Thanks for your comments regarding our wall quandary. I did like hearing what approach you would take if you were in a similar situation.
To refresh your memories our options were:
1. Leave the fibro as it is.
2. Disguise it - leave the fibro, but nail ready-made MDF VJ (vertical join) panel board over the top.
removing D mould which formed the frame and sill for the windows. This photograph is for Melissa.