Metal in Filter

I have had a sweet running 912uls for 900 hours, in fact it still runs sweet, but I just did a routine 900 hour service and 50 hour oil change and received a huge shock! When I cut open the oil filter as I always do, this time there was a lot of metal flakes in each filter pleat. They all seem to be shiny silver color or dark silver, not yellow or brass color. About half of them are ferrous (magnetic) and the others are non-magnetic. They are hard like metal with a very few being soft. I had an oil analysis done at 850 hours and all was normal. I did not take a sample for analysis at this oil change. 

Some recent engine history: At about 850 hours I sent the engine to a Rotax service center in Arlington, WA and had a cracked ignition housing replaced. While it was there, they also inspected the gearbox and replaced spring washers, etc., and rebuilt both carbs, and replaced coolant hoses. Since then it has been running fine for 50 hours.

I am now afraid to fly it! What should I do next?