that sheet has been long gone. This is a really rough shape car. It belongs to a friend who passed away 2 years ago and his wife won't let the car go and had me freshened up the drivetrain and rewire the car as her husband messed up the wiring over the years he had it. She wants to keep it in the family and have her son take her riding in it on occasions. I happened to notice this disc welded to the frame and was curious of what it was for. Thanks.