Go with new brass tubes, they are $5 ea. and you'll likely have trouble getting a good flare seal with the old brass. Damage may be all but invisible. Flaring tool is $20:
https://www.amazon.com/520290-1-Drai.../dp/B0082ANA0C
You'll likely need a longer bolt.
I used 3M 4200 for sealing figuring some flex would reduce possibility cracking and separation with weather changes,