Look at the radiator from the back side unless you see rotted out cross fins from the front. In that case, change the radiator without even checking from the back. If 5% tp 10% are missing from the back, you definitely need a new radiator.
For fuel economy, the vacuum advance has to work, not just hold vacuum. If the breaker plate does not move when vacuum is applied to the advance mechanism, replace it. Replace all rubber vacuum hoses that have hardened or cracked on the ends.
I almost forgot, make sure you have the hot air tube that goes from the exhaust manifold to the air cleaner. If it’s missing, you will use more fuel. The engine is always supposed to get some warm air. When warming up, it is supposed to get even more warm air. Check the heat riser operation too.