Hi ZahnZee / Guys,
Great to see you taking this on. If you are interested and if it's of any use to you, you are welcome to the work I have done with a similar project. I worked on it for a few years (a few FM versions). I haven't touched it since FM20 (family commitments put an end to that ). I'm not even sure if the data imports properly into the latest FM23 version, or if you can import parts of the data to use or add to what you already have. I am not super skilled with the advanced editor to really go into fine details though I really wanted to, but for me there was just too many errors using it.
What I ended up with was the entire football structure in RoI, with a fairly large amount of regional cups; working perfectly in FM20 (so if you have that version installed throw in the file and it should be good to go); anyone who is interested/skilled enough using the latest editor and is interested in cleaning this up for FM23 and getting it up and running, go for it.
ADVANCED 4.0_007_WORKING_OTC_History_VER_05.7z.001
Had to split the file. ADVANCED 4.0_007_WORKING_OTC_History_VER_05.7z.002