oh snap! looks like yours tracks abit further forwards than mine, top tip, when you remove those L shape braces DONT use the impact gun, i didnt think about it before i did it and i ripped the anchor nuts out
most of the steel that i have cut out has been just under 1mm, which is 20g, that thickness is easy to shape. if you havent already got them, a bender, hammers and dollys and a roller have been invaluable to me so far, and i am ordering a shrinker/stretcher and bead roller so i can do the sills more easily. i will post loads of updates of all my trials and errors, this is a problem thats only going to get more common. so people should see how to rectify it,
i am not a metalworker by trade, i am an avionics engineer, so circuits and wires and crap, i have taught myself how to weld and am still learning tons about metal work with every hour i spend in my garage.
EDIT: put a link to your build thread in here if you have one!