I'm guessing that the series on Toccata Classics will get to this work (the first volume, released recently, contains his sonata in D minor of 1901), but until it does, I thought I'd link the digitized manuscript, at U. Frankfurt, of his sonata in G major (dedicated to Jelly d'Aranyi, and it's among his last works, as he finished revising it in April '16 and died at the Somme in November...) that I just noticed. (https://sammlungen.ub.uni-frankfurt.de/musikhs/content/thumbview/6802856)