Sure. The filename is the original post. it did not exist publicly on the internet before that post. Pic related was published before raika put it on the internet, which made him a bit angry.
It's one of several stitches that people made from (C97) [Chillin Party (Raika9)] Misaka Mikoto Shashinshuu 10 (Toaru Kagaku no Railgun). It's currently uploaded to exhentai
That one was stitched on /a/, this one was stitched on /e/ (they forgot to remove the stables), and the one above that >>2173225
i think was done elsewhere and posted to danbooru(?)
There were 8 images in that artbook that were split across two pages, so far only 4 have been stitched, and only two cleaned.
The imouto one from >>2166554
was cleaned too but it's huge (60mb) https://files.catbox.moe/b2wqkc.png
Here's two that have been stitched but no one ever bothered to remove the seams:https://files.catbox.moe/tvmjwa.jpg
(which is >>2173224
but without the filter)
(155MB file, mikoto in a swimsuit)
I don't think anyone has bothered to try to align/stitch the cover or the black pages.
There's someone on /a/ who has been uploading railgun/index artbooks every saturday night (EDT) every week since December. She's done several artbooks but also a lot of ero stuff. They post raika, pyuma, tanaka yuuichi, and others on occassion.