The bell coil is NLA but if its still in the engine its likely it can be repaired. Its just a coil of wire and if there is a break is usually close to the end of the wire.
Not sure how comfortable you are with removing the shell but if you do you can see the coil and follow its wires to the connector on the bell circuit board. Pull the connector and read the resistance between the two wires. It should read about 4-5 ohms. If you decide to try this then report back with the results.
I have bought new bell coils and had one open circuit from Lionel. Easily repaired.
Pete