Greg is right safety 1st.
I never repaired any wheels, crack check yes. My feeling is cracked wheels should be repaired by a qualified individual, which will be at great cost.
Best rule if cracked = wall art!
Last, they are a wheel that requires PM, Lynn and Fran gave me the tools on that which I have shared.
Oil Oil Oil and look at them to be sure they are good.
If cracked you will lose air. If not they may seep but will hold over time.
If you dont want the headache buy alloy!
Oiled and not pretty, Mags on AC#1085