A mysterious (Single Beat!) Chopin score, but who is E.L.Gratia???

Perhaps you could help me out with this: there is little known I believe on this Mister L.E.Gratia, who was a pianist/teacher around 1900. I found one Chopin etude edited by him and published at Philippo in Paris 1912. It doesn't have Chopin's metronome number of 8th = 100 for his etude opus 10 n°3 but... 8th = 54. And of course (yes) there is almost nothing to be found on this Mr Gratia. Perhaps you can help me out with this? -- 🙋If you want to support what we do: ▶  / authenticsound   -- 💿 My recent recording of Pachelbel's Hexachordum Apollinis (Vinyl, CD, Flac) here: http://bit.ly/Pachelbel_Hexachordum -- 📩One weekly mail in your mailbox? 👉http://bit.ly/as-mailinglist -- 👩‍🎓 Check out my course on Keyboard Technique: 👉http://bit.ly/Keyb-Tech -- 📱 Website: ▶http://www.authenticsound.org