Steen Winther
Maybe Hardi (one of the founders):https://grabcad.com/hardi.meybaum
That would be a good guess.
using the "wayback Machine" the first time members are mention is 2010. Before that it looked like a place to order drafts to be produced. Some names include:
Indrek Narusk - Uploads from 2010 to 2013
Kuldar Krabbi -??
Hardi Meybaum- 2010-2011?? Mentioned by name in some projects by Tommy Mueller in 2014
Andri Laidre - Uploads from 2010 to 2012