Here is one original Hepco soft large case which was made for the Porsche 911/912. It has a pebbled finish on the vinyl as opposed to the cases that Hepco made for Mercedes which were smooth. I added a photo of both to show the difference (last photo). This information was provided to me by the Hepco expert in Germany (second photo).

The case measures 25.5 x 17.5 x 6.5 inches. The latches are made by Tip Top.
It comes with the key tag and the quality control paperwork.