Aviation Oxygen Tank needs to be filled but where.

I just realized that I have a new/old oxygen tank in my attic that my step-father had as a backup. He said he never filled or used it and even though it was made in the late 70's its in brand new condition. Anyway I decided I was going to get it filled and use it since I have it but I cant find anyone that will fill it in the Chicagoland area. Does anyone know where I can get this filled? I tried 3 Airgas locations and 2 fire extinguisher recharge companies that I use for my CO2 and all were a no go.

Try a medical supply house or ask at a local hospital.

Try your local airport FBO. I'm not sure if they'll fill it not, without a hydro within a certain period of time. I'm not sure of the restrictions on this. But, it is worth a shot. You can go to www.airnav.com and find the closest airport near you. Check the FBOs that offer "oxygen" service. Good luck!