Ok I'm not seeing it.
When dealing with valve covers it's not usually a shape problem but a height problem. Obviously the cx/gl500 valve covers are the shallowest. When people but gl/cx650 valve covers on their 500's it's only a matter of having the right valve cover bolt. So if you use 650 valve cover bolts to hold a 650 valve cover on it will work.
The turbo cover is probably the same.
When dealing with valve covers it's not usually a shape problem but a height problem. Obviously the cx/gl500 valve covers are the shallowest. When people but gl/cx650 valve covers on their 500's it's only a matter of having the right valve cover bolt. So if you use 650 valve cover bolts to hold a 650 valve cover on it will work.
The turbo cover is probably the same.