Refrigerant never gets old. If the coil never got cold, it's becuase either the system leaked or because the compressor is bad or not receiving power.
If you are worried about freon leaking into the house, don't fret. It's not flammable or toxic. It does displace oxygen which can cause asphyxiation, but there is nowhere near enough in a chiller to run any risk of that.
Is it a drop in chiller? They are notorious for leaking. Not very reliable IMO.
Your repair guy may be able to do something with it, but also may not. Just about every car on the road uses R134A refrigerant. Many chillers use this too, but many also use R22, which you have to have a license to purchase.
The other thing is that every car has schrader valves that allow a connection to the filling equipment, but most chillers do not have them, instead the manufacturer welds the fill lines closed, so your guy may need to have the means to attach schrader valves to it.
Anyway, he may very well be able to do something with it, but he may not. If not, most small appliance shops will probably be able to help you.