1956 GE fridge requests freon? I have a 1956 GE combonation fridge that I restored. I love...

I have a 1956 GE combonation fridge that I restored. I love it! But it is not keeping things very cold these ultimate few days. Does it need freon? I have be using it for about a year now near no problems. If it does need freon, how do I put it in?
Answers:    MAY NEED TO DEFROST IT,OR IF THE COILS ARE FULL
OF DUST BUNNIES
if theirs no service ports, they can be added to charge the system. you have need of to have a tech put a set of guages on it to check pressure. it takes a different refrigerant that may be available in a minute. i know it wont take r 22 , 410 or 134a for autos. certified ge repairman is the one id give the name. Isnt' that the year when they required a block of ice to keep things cold. (The artistic "Ice Box")?