Yes just measure the load at the beginning of the test and again near the end of the test( before removing load), and of course how long the load test was performed, voltage before, voltage just before ending test and voltage an hour after ending, and again X amount of time after load was removed. and we can make educated guesses as to how much life/ capacity/ ability these batteries have remaining.
When discharged, the charging amperage the battery accepts, how long t accepts it before voltage rises to 14.7ish, and how long it takes for amperage at 14.7ish volts to taper to 0.66ish amps, will also be revealing.
Much much more revealing than what you have done upto now.
