Just leave the originals alone. If you don't have the nerves for playing a very old game in an emulator and doesn't enjoy it because the visuals are not appealing, then just play something else. Or name your project XYZ and then tell in interviews that you asked for permission to copy everything and now call it project XYZ.
The trajectory will be:
- look we have created system shock remake
- look this is our new game, you know us, we made the system shock remake...
It's like raise dead+necrophilia that results in some new abomination later on :D.