I got the same problem here and I am using the latest OOG version, which it is built for gracia final. Not gracia epilogue...
I think the only way here is if we can massively modify L2InfoB.dat not line by line where the broken ID's are BUT entire file at once. I created itemname.txt, npcname.txt and skillname.txt by extracting information from L2 Gracia Epilogue client but I cannot import them at once inside L2InfoB.dat... If anyone knows some way to import entire files in it please share that info.