The Vitessa L is the folder with barn doors, and has a meter. The Vitessa T is the non-folder with interchangeable lenses. The Vitessa's are VERY quirky. The RF is a nightmare to align. The Kodak Retina IIIc is a much better choice. Of course, it does not come with an Ultron or Skopar.
I have the Vitessa T and Vitessa N. The latter does not have a meter. These are big cameras- I use a Nikkorex Case for my Vitessa T. The L and N are the same sized body, have the barn doors.