No drawing. We can copy it.

Reverse engineering in Perth from the worn or broken part: we measure it, work out what it was before it wore, draw it and make it.

On a worn part, the surfaces that didn't wear, such as shoulders and faces, still show the original sizes. Standard fits and threads tell us what each size was meant to be, and the mating part tells us what it has to fit. The machinist works out the rest: how much has worn away.