Compound angle mortice and tenon joint - 2

Thanks to Kari Hultman, who refers on her blog to a French Woodworking Video from 1912 of the Ina: La fabrication d'un siège à l'école Boulle, I saw a manual method for making compound angle tenons.

The video shows many interesting details in the making of a Louis XV style seat,  that has by its form only angled joints. Early in the video a wooden leg vise is presented standing proud of the surface of the workbench

[edit] Through a post of the Part Time Woodworker I discovered an image of the same leg mobile vise (étau) in a Chris Schwarz post displayed in a catalogue from La Forge Royale

When it comes to cut a tenon a square frame-vise is attached to the vise.  The top surface of the frame is used as a reference plane for cutting the tenon as it stands square to that surface and the shoulders are set parallel to the top surface.
The tenon shoulder height is set above the frame top to leave room for saws and sawing.  Then a template is used to mark the tenon.

Sawing the shoulders is done with a plane like block saw,  with a horizontal blade on it side,  resting on the horizontal frame-vise. The block saw seems to have symmetrical handles to work on both sides and has most probably symmetrical teeth.
After that a frame saw is used for the vertical cut. Just straight down,  and not a safer three step method with reclamping as proposed by for example Robert Wearing.

During the whole tenon cutting process the piece is attached only once and that's even before most of the markings. After seeing mainly router solutions for compound angle tenons,  I was happy to find at last a hand tool method.