Since I had the props off I figured I should check the drive oil "just in case". Well, the "latte" colored stuff that oozed out at first is pretty heartbreaking. It looks like I got some water in the drive.

Also, though I can detect no external sign of a leak, the oil level was pretty low.

I estimate less than an ounce of water was mixed into the oil, but the drive was close to a quart low on oil. I didn't do the last oil change, so I can't be certain if the mechanic put in enough or not, though he is an experienced Volvo Penta mechanic.
My first thought is to drain the outdrive, run some lightweight oil through from the top to help flush out any water, then pump in fresh gear oil and button it up with fresh o-rings. Then give it a run in the water and re-check after.
Am I likely to cause harm doing that?
Anything I can check before handing it over to a mechanic to pull the drive and charge me big bucks?
Rich