Best of luck - I had many happy memories on RS, both pre-2008 and after, and even the experimental HTML5 client. No archives sadly
If you're not aware, RuneScape was an online java game created in 2001. The game was being continually updated with over 400 different versions existing, but the developers didn't implement any full version control until 2012 (aside from a single tape backup they found of 2007).
Therefore we're appealing here to see if anybody has it saved on an old computer, or hard drive. Even if you just played it once for a minute to see what it was then never again, you should have the full game data, because it was automatically downloaded via browser.
The RuneScape Archive created a new open-source search tool which you can download here: https://github.com/edward4096/rscachefinder/releases – this will automatically scan a drive to find all the RuneScape game files, and combine them into a single file you can upload. (It works all the way back to Windows 95, so if you have any old machines you could put the tool on a USB and run it from there).
If you would like to search manually yourself, check out our page on the Lost Media Wiki: https://lostmediawiki.com/Runescape_(lost_builds_of_online_game;_2001-2012)
If you’re interested, you might like to check out our website: https://rs-archive.neocities.org/ which explains the project in full detail, addresses frequently asked questions, and includes a link to our discord server.
Thanks in advance.