If I could see a bracket in the flesh or a good drawing I’d be keen to go the hardware store and buy a piece of sheet aluminium and have a go at making one. A vice for bending, basic tools and some rivets for fixing/bracing corners together should be all that’s needed I guess. . It’s not as if it’s on show where a fancy version may be desirable.I don’t care who makes one, but a bracket doesn’t take an engineering genius or a lot of expensive materials so whoever does it, I reckon they can supply one at about half the price of black sheep delivered in Australia and still make a profit