I made it work using your tutorial as a base, thank you very much.
The only real problem I found is that the data folder you're linking doesn't have all the sprites and images for some of the recent gears and items. I had to get some from external sources.
Having your own offline ragnarok is really, really nice!
Now all I wish is that I could make Openkore work in my own offline server, I tried EVERYTHING I could possibly do and couldn't extract recvpackets.txt from the 2015 client I used no matter which tool or guide I tried.
Anyway, thank you once again for the awesome tutorial!