Pre 1950s rides of LFGSS: old bikes, vintage rats, classic lightweights

Looks pretty worn out judging by the chain wear on the backs of the teeth.

Looks a bit far gone to me, although as it's a single freewheel you might gar away with it as no gear changing etc

Utterly knackered .. from what we can see. Looks like the chain side plates are going to hit the body of the cog, so slippage and noise will occur. Post a pic of where the teeth come out of the sprocket body, I expect there will be chain marks on it.