Have you exposed the 1/2" alky back to its Tee connection with the main water service? If so, you could replace with a single length of 1/2".
If its not totally exposed or accessible then cut the pipe and use a new length from the repair location to wherever you want - that way there's only one repair fitting below ground.
Take an off-cut of the 1/2" to the plumbing suppliers and tell them your story. You will need a straight coupler.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local