"When another friendly ship at Range 1-3 is attacking, if you have no stress tokens, you may receive 1 stress token to allow that ship to roll 1 additional attack die."

I now take a Rebel Y-Wing and maunt a turret and then the title "BTL-A4 Y-Wing"

"You cannot attack ships outside your firing arc. After you preform a primary weapon attack, you may imediately preform an attack With a (Turret) secondary weapon."

Now I will ask you all this.

If Jan Ors gives a ship +1 attack die, is it then not for both attacks?

PLEASE Help me out here. ...

You'd make the first attack and get the stress token. Since Ors' ability states "If you have no stress tokens," you couldn't use it for the second attack.

On the face of it the idea seems sound, however the FAQ (page 12) has other ideas:

Jan Ors’ ability only applies to a single attack. For example, if a ship equipped with Gunner rolls the extra attack die granted by Jan Ors on its first attack and misses, it does not receive the die from Jan Ors again during the attack granted by Gunner.

Edit - Oops - forgot the "if you have no stress tokens" condition - although that doesn't change my answer it wraps up the question - good catch DailyRich