Don't use WD-40. It can silver the decals if they're at all vulnerable. That calls into question the other advice. I think shoe polish would rub off on fabric until it was gone then the scratches would reappear.
I've seen far better suggestions for refreshing a finish that isn't in dire need of rehabilitation. I am however the wrong person to ask about the best chemicals to refresh a machine. I get cloud out of wax unless I use a power polisher and the FW is way too small and complex for that.
I'd be curious what a good coat of wax would do. Wax can fill the scratches creating the optical illusion of a flat surface that reflects evenly - i.e. shine - and it's a lot safer than the 2 products you've had recommended.
Shoe polish is fine for the case.