I am very new to Solidworks and I am teaching myself via a ton of YouTube tutorials, so please bear with me if I sound like a complete novice.  This model has a taper when viewed from the left or right planes. I need to use the top plane as a Neutral Plane for the origin of my Draft, however I am getting the error that "Non planar surfaces cannot be selected as Neutral plane for draft".  I am assuming this is due to the fact that the Top plane has a radius to it?  Essentially, when the model is viewd from the left or right, it should measure 62.00mm across at the bottom and 52.39mm across at the top.  The front and rear panels will have a slight inward angle.  Hopefully that makes sense.

Is this possible to do without totally reversing the model's workflow?  I believe I would need to use the Top radiused plane as a neutral plane to get the result shown in the first photo showing the side profile of the the physical model I reverse engineered below. Thanks in advance for any insight you guys can offer.  I am really enjoying this learning experience.

Message was edited by: Torrey Hughes