The rails and screws were removed from the drawer and are included - photos of the gold coin repository for dimensions are shown.  It seems like the 2-3/4" width is quite common; different models seem to vary in the length.  This one is just over 4-3/4" long.  It looks like the lock and flanges are in the same place regardless of length, so you might be able to have a machinist reduce the long end (away from the lock) to fit your application if this one is too long.  Check dimensions of what you have to see if that would work if this is longer than you need.