If you're working in timber as here, this is how we'll mount the chassis on the skis. I was going to fix it at mid-height but the advantage of aligning it with the top-side is that there will be fewer parts involved: these can eventually be hung with three-way tube connectors at this point.
In view of the fact you cannot drive a pin into each leg from the side as it stands, fix this first leg with angle brackets instead for the moment.
