OK, Dimensions.
The entire unit is built from 18mm thick stock of your choice. I have used both fully seasoned Radiata pine and Hoop pine plywood in previous chairs. I guess one could use KDHW but it might be just a little heavy. These ones are Radiata pine.
For the 3 pieces ready for staining in the attached image:
Front and rear legs are 900mm long with the front leg being 140mm wide and the rear leg 80mm. When fully opened, they make an angle of 45 degrees at the hinge point
The bottom of the rear leg is chamfered @ 22.5 degrees (if only I could cut that accurately

) so as to rest flat on the ground when the chair is opened fully.
The front cross arm is 600mm wide, 145mm high in the centre 140mm, tapering to 70mm high at the ends. The bottom edge is chamfered @ 22.5 degrees same as the rear leg.
Both the front cross arm and rear leg have 20mm thick hardwood feet glued to the chamfered edges.
More to come as I progress.
Cheers,