I've done a quick copy of your plug and a video of how to get better results with ViaCAD v7 for this task. It's not perfect, but it might help you along a bit if you can't find something better at a reasonable price.
I've attached an Illustrator and a DXF file of the plug for you to look at.

Martin.

http://screencast.com/t/VmxGbV6lVI