Without any doubt the LLFM is an outstanding yacht and has many followers,but there are better designs to consider,having built 6 land yachts from a Cl5 ,a copy blokart and class5.6.s. both LLYM style and Variations of it. I suggest.....
Once you finish your LLFM the next one you build and since this is very addictive there will be a next one

consider a Y framed chassis. You will be impressed with the increase in overall performance and ,comfort.
When building to fit in with the mini specs the basic dimentions generally prevents wide rear axles, wider rear axles give benifits....A bit of suspension , the longer downwind axle absorbs the sideways force in a gust,then gives that energy back as the gust eases ..both result in more speed.
You can build a Y frame to conform to the rear axle width but have longer axles thus gaining the above,the seat can then be dropped into the space between the Y thus lowering the C of G.
Whilst the LLFM is all about building from any material that is available free(Lamp posts etc).
Stainless sections are just as weldable (Correct wire and gas) as mild steel which needs painting and rust protection.welding galvanised mild steel,In my view, is asking for health troubles from the zinc coating,even if ground off to weld,you can,t get rid of it from inside the section.
Most of the top racers in the uk,one of our locals compets at international level,all all useing Y framed designs. PLenty of advice on here.(You do know that by searching for seabreeze construction/general page 2)will bring up all of the old posts going back year.
Have a look here at Les bythenorthsea photos some excellent builds and ideas www.seabreeze.com.au/Members/Profile/Details.aspx?member=Bynorthsea
Good luck