What are the indications of a ring job?
Using oil and seeing some smoke out the exhaust.
That could also be a sign of the valve oil seals wearing out.
To test for worn piston rings you will need a good compression guage to find out how much compression the engine has. This test is always done with the carburetor or throttle body at a "wide open" condition.
First, test the engine just the way it's sitting after the last shut down. Take several readings and record them.
Once this is done, pour about a tablespoon or so of engine oil thru the sparkplug hole.
Then, kick over the engine a few times.
Now, retest the compression several times, recording the values.
If the first and second test readings are very close and 120 psi or higher the piston rings are doing their job just fine so any oil burning is due to leaky valve stem seals.
If the first test is below 90 psi that only indicates something is quite wrong.
If the second, oiled test shows a marked improvement in compression (like the 90 psi reading goes up to 130 psi) that indicates the piston rings are leaking. They need to be replaced.
If there is less than 10 psi difference between the first (dry) test and the second (oiled) test but the low compression stays about the same it indicates a burned valve. This is usually the exhaust valve. (This assumes the valves are properly adjusted because a mis adjustment of the pushrods could leave a valve hanging open.)
Hope this helps.