72 Charger rear spring shackles

My son picked up a project car - 72 Chrgr - and the shackle mounts at the rear ends of the leaf springs are almost completely rusted away.  (I drove it home for him - he was 15 then - and I'm lucky the rear axle came all the way home with me.)

I've seen aftermarket fixes for this fairly common problem, but at approximately $500 for both sides, that would double the price of the car.

Has anyone successfully welded a set of mounts back on? Is the geometry critical?  (I can weld in a new set of angle-and-tube superstructure to which I can mount some kind of shackle mount, and I just need to know if someone thinks that's a bad idea.

Thanks!  

Start welding, just keep it as straight as possible.
Doc