Frostburgh isn’t in the game client. Simply put Frostburgh is gone and no longer in the game.

There is no research for the files. They simply aren’t in the client. You’d need either a FAT client or a client that was abandoned during around the Frostburgh era. Not 100% sure on either of those but I’m fairly sure if you had a client that wasn’t used since Frostburgh release you could access it. And as for the FAT client only a handful of people have that and aren’t interested in uploading it. Not 100% sure if the FAT client even has access to Frostburgh though.