Anything can be repaired. Just how and at what cost are the questions.
One option might be to find a car with rust free supports. Cut those out and weld them onto your car. Or if there is a good shop in your area, perhaps they could fabricate the replacement. This would cost some $$$ and you would have to decide whether rest of car would make it worthwhile
I wouldn't be concerned about proper weld repairs. Mercedes 107s were delivered with badly designed subframe mounts. These were repaired by welding on reinforcement plates. On my 300d. Part of my rear frame rails had rusted. A local shop fabbed new pieces to fit. This some time ago and still good.
Maybe see if you can find another 240d cheap and make one good one from the two!
Good luck whatever you decide.