Gerhard Helzel was an early pioneer in creating digital realisations of obscure music. I did not know him, but I imagine some of you here did. I've been informed that he died earlier this year. His website appears to be already defunct, but you can still access it via the Wayback Machine (https://web.archive.org/web/20250812223847/http://www.romana-hamburg.de/).
I encourage people to explore it, and download and archive anything you can find, as there's no telling how long it will continue to be available. Admittedly, the technology has improved since then, and not all of it holds up to modern standards, but there are some hidden gems to be found there.
Yes, Helzel's site appears to have been taken offline only last week.
It's quite difficult to get his realizations, though, as he sold them commercially and to my knowledge they were never made available on any online medium. The Staatsbibliothek in Berlin possesses some of his renditions (Kaun's 1st Symphony, the first Piano Concerto and Walter Niemann's Waldidyll), but he also worked on other interesting composers such as Hugo Rüter.