For secrets like that that require the room to be uncleared to access them, you'll have to restore to a point before you cleared that room. For me, "
Room Start"
in the restore menu seemed to work. Keep in mind that this will put you back in Chapter 1, so make sure that you use a restore point in your current endgame file so that you know where to restore back to after completing the secret.
Also, not sure if you know this or not, so I'll just say it anyway, but with collectables like the RCS stamps you need to collect all of those in a single save file. If you restore to a room with a stamp, solve it, and then restore back to your endgame file, you won't have the stamp on that file. Fortunately it is possible to backtrack to all collectables in this game, so if you do find your missing stamp go to your endgame file and walk to the room from there.
To avoid confusion with the save files, it is good to have a "
default"
checkpoint that you always use before restoring. I personally used
Click here to view the secret text
×the lonely campsite
since it is quickly accessible from the map. Other people prefer to use
Click here to view the secret text
×the checkpoint by Beethro's inventory in the annex of Lost Central Station, since that's where you can check on what you are still missing in terms of collectables
.
____________________________
106th Skywatcher