First, neither of those two verses say "Gentile".
Second, I don't need to look anything up as the verse provides a CLEAR context.
Gal 3:28 KJV There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus.The second and third "neither" show that Paul is exhausting ALL possibilities. There is NO reason to believe that the FIRST is any different.
No matter how hard you try, the Israelites from the 10 Northern Tribes were NEVER Jews.
(Gal 3:28 NIV) There is neither Jew nor Gentile, neither slave nor free, nor is there male and female, for you are all one in Christ Jesus.
Second, I don't need to look anything up
You really should because you are very confused.