This is so very creative! Much fun to look at and study - your photographs are absolutely terrific, and I love how you put them together to tell the story.
The antique-ness, the recounting of your tale through artifacts and old writing, is a lovely tribute, a meta and tie-in, to DH's heavy use of news stories and letters, memorabilia and memories to carry the story.
Makes me wibble at the sad ending... but the romance of the materials and lovely workmanship make the prevailing note one of beauty, and the distancing through the photos and timeworn media softens the pain. Snape is reunited with Harry in this enduring artifact. And how cool that it's a key, yes? The key to Harry's success was his closeness to someone he ultimately abandoned, just as his mother had turned away from Severus before him...
All the interesting little details you've put into this! Neat, just really neat. *mind boggles at tiny-ness of it all*