Here you can see the pins, with reference to the cut corner you lost the Vcc, that is the voltage, I think it works because the SIM is pressed in the case and makes contact with what has been left of the contact
https://www.extremetech.com/wp-content/u...iagram.jpg
a basic principle in practical technology is that if something works you leave it as it is
I don't know whether solder would stick on aluminum, in that case I would stick a small ball of soldering material but you may run the danger of scratching and destroying the SIM, just leave it as it is.
https://www.extremetech.com/wp-content/u...iagram.jpg
a basic principle in practical technology is that if something works you leave it as it is
I don't know whether solder would stick on aluminum, in that case I would stick a small ball of soldering material but you may run the danger of scratching and destroying the SIM, just leave it as it is.