HI Peter, I have checked the lagerkatalog. We could use some square tube in Al (50x50) or the same in Fe. Alu is fine and light, but Fe is 2.09CHF/kg whereas Al is 5.37CHF/kg. So we need a very good reason not to make it in Fe. We could imagine doing this in parts which are then bolted together. I will think again for a design. Best regards Francoise