Oh well, 0.9mm sheet metal won't last forever. I should just buy a new BBQ every 7 years, right? The problem is the great advancement in BBQ manufacture in the last 7 years is that now the entire BBQ is made from 0.9mm sheet metal, including the burners! Luckily, having just completed my welding short course, I am in a position to make my own using ye olde worlde cast iron gas burners left over from the old BBQ. I wasn't able to make the whole thing from my scrap bin so I had to buy some of the longer lengths. Whilst distracting my metal merchant with my $30 order I had a good 10 minutes to rummage through his pile of offcuts and found enough shorts to made the cross members. It is probably 60% scrap material.
The BBQ has been made in two sections. The main frame and a separate burner sub-assembly which bolts inside. I still have to figure out how to fit sheet metal wind guards, drip tray and fit the old hood but so far so good. It probably isn't and Masterchef approved stainless job with wok burner but it will keep me in wood smoked porchetta for another five years or so.