that revisions you are using are Gracia Epilogue
If you wanna add a interlude buffer you will have to change somethings:
1) The buffer folder (which should contain the .py script and maybe some htm files) must be placed in scripts/custom
2) Go to scripts.cfg and add, at the botton: custom/yourbufferfoldername/__init__.py (if the script is called __init__.py, otherwise, put the script name ended in .py)
3) Be sure you open the scripts and change the imports from net.sf.l2j to com.l2jserver
Important
From interlude to epilogue there has been a lot of changes in the core, that means the imports may change (due class move from any package to other), and some methods from core may not exist. On start up, the methods which doesnt exist (if theres any) will prompt as an error, so you can know by that error what doesnt exist and will can look for other to replace them