I hadn't realised there was a second ring bracket on the intercooler. I've just had another look and there is no sign of one on mine. I can see the lower peg on the radiator, though.
I did experiment with a support bracket which hooks under the intercooler and the top end is secured by the bolt holding the fan shroud to the radiator. Unfortunately, the only piece of metal I could find is too thin and bendy, so I will need to source something stronger if I pursue that.
For the time being, I've lifted the intercooler up into the correct position - the remains of the ring still locates on the peg - drilled a hole through the web and secured it to the subframe with a cable tie.
I might also add a screw and second cable-tie, as you have done.