I have seen worse sheet metal conditions than yours. It is still recognizable as to year and makes some had only the top of the belt line left with everything below rusted away.
Your complaint about a body shop is common all the way around the world I am afraid. Taking it to a restoration house (specialist) or finding a sheet metal fabricator that makes and welds in his own patch panels is best; but hardest to find. Congrats on getting your car back on the road to recovery!