The command Silhouette looking from the pull direction will give you a "dirty" solution that will generally include the parting line and a bunch of other stuff, after some cleanup, you can usually end up with something workable.
Got to admit that that's the solution I've been trying out today. But the issue is that it does not do a good job on complex polysurfaces - each surface gets an outline , which is a major pain.
I've hoped that mesh outline will work - sadly it is only a projection upon a given cplane. If the result of the meshoutline would actually stay on object that would be the solution :) .
Will try to get it work with some projections - will share the results :) .