I think 2004.05.27 is the correct release date. Everywhere on booklets and the disc it says (c)2004 UNKNOWN.
Also (archived version) of Project-rs website confirms the same date.
http://web.archive.org/web/200406071...eatsItself.htm
And (archived version) of Clubhobi page (22 Jun 2004) says: 好評発売中!! (on sale!!) which means it was released prior 2005.
http://web.archive.org/web/200406220...p/hbr_hri.html
. . .
Project-rs.com was a website for 'Project Repeated Scene' trilogy consisting of 3 episodes.
ABANDONER - 3rd episode (released 1st)
Lost Child - 2nd episode (released 2nd)
Origin of Repeated Scene - 1st episode (released 3rd) unfinished/never released.