The 8053 String Not Found message is only for the success message, and doesn't affect combine chances. It is the
success message. I think it used to be "You have combined these items to make something new."
Just edit eqstr_us.txt with a non-insane text editor (Notepad does not count as non-insane; Notepad++ is fine.)
This system was implemented so you could translate EQ into different languages - just load the text file of the language you're using and BAM, all the messages in your native language. The text can be anything you want. You can do this, for example: