Orillion

Apologies if this is a stupid question, but I'm trying to find a way to implement the Pre-renewal GUI (with the menu buttons to the right of the status bar, for example) in newer clients. I don't know that much about Ragnarok's internals, but as far as I can tell it seems to be baked into the client. (At least, if it's a set of files in the data.grf I can't for the life of me find it) Can someone point me in the right direction for this? My preferred solution is something that allows people to choose on an individual level which UI they want, but just knowing what to look for would at least give me closure regarding whether this is doable or not.