I don't know for sure, but I think they are the same person from postings in the Howlett family forum (ie see message 555). The birth year matches and both had a sister Annie. We just need more original source information. She may have changed her preferred name through the years.
I'll send you my current info on the John R Portis line via email this week. I and my father(Sr.) were at the Portis reunion in 1998 and we visited the Portis cemetery in Patrick Co VA. I think Rufus may be buried there. I took some pictures but found nothing on him in the ones I have. I want to return someday and take more.There has been some discussion about having another reunion, but nothing definite yet.