conical swept cut

I posted in another area and it was suggested that I post here.  This is my first time to ask a question and I'm hoping with all this knowledge available someone has an easy answer.

The file I have attached showes a part that I need to make a mold for.  I thought I would create a swept conical surface to be the parting line.  I have not had any success.  Does anyone have a better idea.

SolidworksPlastics And Mold Design