I was trying to find these to point a young fella in the right direction. Thank you Gizmo for keeping them on the boil for us.
Here is the link to the plans.
www.seabreeze.com.au/forums/Land-Yacht-Sailing/Construction/Lake-Lefroy-Mini-Plans--The original post by Landyacht seems to have disappeared with all his photos. Here are some updates that Stephen (sn) suggested and I totally agree with them as follows.
Not shown in the plans as these improvements were developed at a later date :
: mast step can be vertical [instead of the 10 degree rearwards lean] - this has proven to work very well with unmodified windsurfer sails.
: weld a plate over the rear of the chassis spine tube - then the tube is less liable to tear at the axle tube welds due to twisting.
: run a steel strap (flat bar 25mm x 3mm as shown in the pic below) down one side of the mast-step, underneath the chassis spine, and back up the other side of the mast-step. Stitch weld this strap to the mast-step and chassis spine, not a continuous weld. This will prevent the mast step welds from fatiguing and tearing apart due to stress.

Cheers Chook