https://aomci.org/forums/topic/mix-lower-unit-gears-and-gearcase-halves/
Here is background from a previous discussion of your question. It does look like yours are mismatched. I think a pressure test is the way to go. If it passed I would run it a bit, maybe a half hour, then check the oil to see if it is contaminated with water, Do not run for long without checking as these gearcases can run for awhile after the oil has leaked out and the casing is filled with water. But that will ruin the bearings and gears. (expensive).
