I have a pen that has a very small label called "Porsche Design". There is no other identification such as model # etc. I am almost certain that the pen is out of Titanium and was bought sometime in the early 1970s.
Not only am I trying to find out what model this is but also what type of ball-point refill it takes.I have tried many types but so far no luck. Any help is appreciated. Pictures are attached.