How to make a DXF with two planes one???

Hi

I have this file set of dxfs where the parts seem to be drawn on two planes. I want to create a 3d model with them but the double planes causes problems.

Is there a way to combine both planes into one in draftsight to make things easier.

I have added a file for you to look at, and you will see that the outline is on one plane whilst the circles for holes are on another.

Kind Regards

Ian