I did only find two versions of NATural-SOHO.
Vers. 1.55
ftp://149.156.2.19/pub/mirror/WinSit...Tural-SOHO.exe
ftp://debian.lcs.mit.edu/pub/winsite...Tural-SOHO.exe
ftp://ftp.cyfronet.krakow.pl/pub/mir...Tural-SOHO.exe
http://dl.winsite.com/files/112/ar1/...Tural-SOHO.exe
Vers. 1.70
ftp://listsoft.ru/pub/14988/NATural-SOHO.exe