Thanks for all the support!!! He/She is doing well! Yesterday I left him together with my Sebbies and Runners. I did add a couple drops of Ivermectin to his back in case he has lice/bugs/etc. I know he should have been quarantined...but... I thought he needed the company because he could hear them. He took right to the geese, mainly because the runners ran when they saw him. My goose didn't give him a second look, however, the gander spent most of the day bobbing heads and squawking at him. There was a nip or two at the watering hole, but I left them alone. Today, they have been wandering around the yard grazing together. 
I still don't know what gender. I did get my first TWO goose eggs today. One normal one in the pen (Sebbie) and one soft-shelled broken one in the yard after I added the new goose... ... so could it be a she?? I didn't think geese laid more than one egg a day.
It is very tempting to keep him/her... but I really can't. Patti's friend is not ready for geese right now. I will put a post in the for sale/wanted, but if anybody knows anybody in my general area that is interested, please let me know!!! I am willing to travel to meet up, so please don't hesitate to contact me. I will even drive to California if the person pays my gas and lets me stay there for a week!
Sorry, I will not ship the goose.