I wish there was a way to check the bearings without a teardown. I'm sure the filter caught a lot of it, but there is likely some in the pickup screen too. What to do, what to do...
You can look at it if it makes you feel better but as a very general rule, the pieces that come off a brass gear are fairly big and not small pieces.
I'd start by cutting open the filter and see how much junk is in it. That should at least give you a general idea how much of that brass is floating through the engine.
I know it seems like its a quite a bit of stuff that comes off those gears, but really its not as much as you think and like I said they are generally pretty big pieces, easily caught by the filter.