Managed to get my hands on a sheet of 3mm 1050 Aluminium (a test of sheer will if looking for a decent price in these COVID times) so I could hack and fold the under bracket in a hard material. I haven’t used 3mm material before so I was a bit worried about folding and material yield. But no issues forming this part, even after bending the same fold back and forth a couple of times. My brazing skills are very slowly improving. I think this part will last for a while.