Receptacle flush to the paneling
Before you purchase the extenders you should have in hand the extra large cover plates and check to see that they will cover the extra large rectangle in the paneling and that they fit your receptacle shape.

These extra large extenders might be all you need. 

But you should have a package of the plastic shims and/or the RACO sheet metal ring support because if you use the Arlington extenders, the fins might not be large enough to bridge across the top and bottom gaps and you might need to use shims under the extender box fins to provide a firm physical connection. The top and bottom fins don't need shims if the wall around the box is close but if there is a large gap they need support of shims or the RACO sheet metal flush fit device.

Arlington box extender

sheet metal ring support