I would like to know, from where are you taking the information about old chronicles official servers. Is there any site that keeps these? To be more specific for example on C4 or Interlude, how do you check the actual monster drops, chances etc? Or the actual skills stats and chances. L2J is known for all these data to be off, and official servers with these chronicles no longer exist.
L2J is missing data on various things, in part due to them using improperly parsed data and in part not caring to update certain omissions (items and recipe data I know, possibly skill and npc data too). For example, spawn data is completely made up and L2J has no way of using L2OFF spawn makers or spawn territories. Same goes for Hellbound and associated "cycle manager" (L2OFF terminology) things. Zone data, while somewhat insignificant, is also custom and does not correspond one-to-one to L2OFF areas.
Ultimately it is L2OFF data that matters, however you cannot just look it up and make sense. And data alone cannot tell how it can be used, however I'm responding to only part related to data. There are various websites/blogs/forums where you can look up various things too, however fragmented response may be.
And speaking of Interlude. From what I see on Acis conversations, they are using GOD data, meaning there is no L2OFF data that you can find specifically for Interlude chronicle. That alone makes targeting such chronicle for formulas or game behavior very difficult to pin-point.