Jennings 22 handgun

Question
I bought one @ an auction over the weekend. Went in to pick it up @ the gun shop. I paid way too much for it, but they asked me to double check if the gun is legal in Illinois.

Answer
Well not sure what you paid or what condition it is in, if a gun store gave it to you then they should know gun laws for their state they are doing business in.  You can call local police and ask them, but they will need more info.  Why would it be illegal?