I don’t know of any Filcos that ship with a metal case, but at least one seller (mechanicalkeyboards) has the option for some higher end finishes for the stock ones. That I know of, this is the easiest case to find for Filcos and the like; it restocks periodically:
I’ve got one of these; IIRC it’s top-mount. It’s a brick of aluminum - looks quite good but the big thing to keep in mind is that it changes both the height and typing angle; higher up, and the angle is less steep than stock with the feet in use.
This is the top shell I have, which I personally prefer because it retains the original angle and height:
It’s a great looking, super rigid, heavy shell. (The only thing I don’t like is the labeling for the lock lights.) One thing to keep in mind is the very close tolerances around the keycaps - you might be better off removing the top shell first if you want to change the caps.
Speaking of Filco lock lights - they are indeed insanely bright. Eyeball-piercing PlayStation blue. Activate the photonic cannon! When I’m able to visit my dad, we have plans to replace them with much more dim amber ones. He recently put together a small circuit that will adjust the voltage to accommodate different LEDs and brightness levels.