How to install a new horizontal thermo-treated panel?

[anizze]

We shall install new heat-treated pine paneling on the existing painted vertical paneling, the existing one has no damage except for linseed oil blisters, how would you have done it? Would you have screwed directly into the existing panel or would you have used thin battens with appropriate spacing to allow more air between the old and new paneling?

 

[Testarn]

To avoid moisture between the panel layers, I had installed battens as spacers. Then ensured there is a slight opening at the top and bottom to facilitate natural ventilation behind the new panel.