We added an SVX to the "fleet" last August. I share your pain, waiting for parts or having the dealer tell me parts are no longer available. While the SVX is a '92, I started checking up on my local dealer's all to frequent NLA (No Longer Available) answers. As a result, I often use an online Subaru dealer in Washington state. With the exception of the parts that are truly discontinued by Subaru, their price & delivery time has been great...
As far as the luggage shade hook, one of ours broke too. I cut off the back & used a generic, square, snap-in screw anchor with the old hook. Works ok, but could be tighter. I don't think there is a parts listing for the hook. We need to find someone to 3D print the parts...