Cracked aluminium bonnet

[badabec]

Hello, please move this to more suitable location if needed.
My 1972 Citroën DS has an aluminium bonnet (all the classic DS do). It is a massive bonnet. Lazy people drop the bonnet to close it. It has a bonnet catch each side.
The edge of the bonnet has cracked. The aluminium is about 18swg.
How would the brain bank repair the crack? TIG or Lumiweld. The Imperial mike is shown, can't work out the thickness. Being Citroën, you know it will be thin!
Thanks

 

[voipio]

0.0782" ish, so basically 2mm.

 

[badabec]

The rivet heads in the picture hold the bonnet catch. Nothing to stop me adding backing aluminium.
My worry with TIG is that the heat will make the split worse.

 

[Fazerruss]

Don't overthinink it
Lumiweld is crap. Easy job for TIG, sorted.

Here are some 1mm Aluminium (Birmabrite) mudguards I repaired off a Vincent Rapide. They were much worse than your bonet