Question Can these be put back on?

You might want to show us the extent of the damage on the connectors. You could resolder them on, provided you have a reputable repair shop nearby and they have the necessary connector or they can identify the connector in question. I'm assuming it's the connector to the RGB and not the RGB LED strips.

One other thing you could do, is lower the price offered so you can sell the card or, you can keep the card as a spare/backup card or hang it up on a wall for posterity's sake.