Replacing Rear Spoiler/Gurney Tab

I'm getting ready to replace the rear spoiler/Gurney Tab on my Superformance GT40MKII and have several questions for those who may be familiar with how to do this:

1. It appears that six fasteners on the outside of the spoiler have hex nuts or screws which screw into fasteners on the inside of the clam shell to hold everything in place. Is this correct?

2. Are the hex nuts/screws countersunk into the six outside fasteners in a way that allows the fasteners to tighten against the spoiler without turning and possibly scratching the spoiler? Are these nuts/screws removable when you loosen them and then you place them back into the fasteners when ready to tighten everything up?

3. Concerning the fasteners on the inside of the clamshell, do these contain metal liners into which the screws/nuts can tighten, or are these "one use" type anchors that have to be replaced?

Thanks in advance for any help/advice!
/s/ Chris Kennedy