In England we would (and do) say "a box of Lego" and "a camera made of Lego".
Another pluralisation I don't understand is where I might say "we have a long way to go", I sometimes see it written as ".....a ways to go". The a implies singular but ways is plural.
It comes from the other use of the word Lego to mean a single Lego brick, not just the name of the product in general. If you say "a Lego" to mean a brick, then what do you call multiple bricks? Three Lego? Sounds completely weird to me. So it must be a U.S. vs. British English thing.
"Truth and love are my law and worship. Form and conscience are my manifestation and guide. Nature and peace are my shelter and companions. Order is my attitude. Beauty and perfection are my attack."