Let me give you a little more hope. .. .. I actually built the client from scratch, and it wasn’t that complicated.
I’m running it on DirectX 9 right now, but honestly it’d be even better to bump it up to DirectX 10 or higher.
That way you’re not stuck with the old fixed-pipeline stuff, and you could build an even cleaner client .. the code you’ve got is from 2001, maybe older.