Setter's tick against a sketch. Released inspection has dimensions. So not two measurements of the same thing.

Then I wouldn't subtract anything from anything; on a previous bracket discussion I meant compare the contact conditions, not pick whichever support makes the numbers look nicer

Understood. The old sketch doesn't identify the supports either. I've put that gap beside the correction entry for the estimator. Better an obvious unknown than a tidy but fictional cycle time.

Is the person who used that sketch still around? They might explain what the tick meant, even if nobody can recover an old dimension from it