Perhaps it is best to try contacting developers. Not sure, but this seems like
their site, hopefully those are the same guys that may be interesting in releasing the game to public domain. And hopefully they still have it.
I did found
this as well, but not sure what game from series it is and it is probably also shareware demo. But could have some contacting detail as well.
Oh, and if you have any luck, please do share it with us
edit: Hmmm, at the second look, it might not be the same company, since this new one is called "Gaming", not "Games". Worth trying anyway, and look for some other contact from those demos you have. After some googling, it seems that pharosgames.com used to exist, but no more I guess
edit 2: Ok, few more tries.
Try
Adventure Legends link, many their games on CD but could be all demos. Some info and screenshot on this
1999 games page, search for "Cendric".
This one is similar, only installer. And
this is that revisited game again.