Yeah I used to play Eternion-wow quite a bit back in the day, was one of the GMs from Lost City realm.
And yeah, if you have the proof of purchase then you can send it in to get gear for the Eternian-wow realm.
They should respond quickly and give you a price for what you can get. Although, I lost a majority of my donation gear on that realm when the farm able gear got updated, haven't received a response yet about that.
But its worth the try none the less, welcome to IceCold.