Replacement ends are tough to put on right.
If you do this, solder it as well as crimp, and seal or paint the exposed wires.
Using wire as shims is not good at all. All the current is forced to flow through tiny wires. It's better than air, though.
An aluminum shim is OK for now - it is only a very short distance of aluminum .
Brass is better - maybe Ace Hardware has something.
Feeler gauges can be used =- super simple. And some sets have brass ones included - even better..