I also think that they are somewhat short and that the sink alone would be little stable with them. I am still looking for solutions. I will probably also contact a specialized plumbing company.
Hi,
they should actually hold, I learned GWS back in the late 70s.
Back then, there were still some mounts, either the tabs, alternatively there were also such brackets made of cast iron.
Just enter this item number on EBAY: 254191332504
Regards, Olli