Scott,
Thanks for your reply. Yes, I do have an email in to Benchmade asking for the spec on the screw. My gut told me that Benchmade would use a stainless torx screw so I presumed this was an incorrect replacement. My experience with Benchmade has been that when I have aske them a question like this they offer a replacement. I tossed the question out here in case someone has the spec on the screw. I have a variety of replacement torx screws and may have one that will fit.
I might as well work on removing this rusty Phillips head screw this weekend. It needs to go no matter what. I will clean up the thread whole and double check the size in case it has been hogged out.