Oh nice, do they do an early version (with the hatch vent holes pressed into it)? The only difference with early vs later hatches is those vents, so if they only make that piece you can just cut out the vents and patch them into a non vented 1.
I spent ages at my night Tafe panel beating class shaping that lower section, it's actually not flat at the bottom but curved which complicated things for a newbie like me.
The problem though is that often the hatch frame is rusted out also, not just the upper skin.
I have another early hatch I got off someone else who had started to try and repair it, it was a bit beat up. So an excellent guinea pig for trying to repair with a new skin panel like that.