Your pedestal base looks to be the “Plug in” series from Springfield. The one I have is the “Springlock/cliplock” series. If you go to Springfields website, you can see the differences between the 2. The base for mine has an open hole for the pedestal sleeve to slide down into and lock with the clip. Yours I believe has the base where the hole has a black plastic or rubber insert where your pedestal slides into the round, cut out insert. Correct me if I’m wrong.