In your 2nd pic that's bearing material it seems. I have the same thing going on right now. It's the bearings. How many I don't know but my oil PSI fluctuates after the oil is up to temps. I'll try a thicker oil but I know it's a accident waiting to happen.

Goood luck.

 

I still think its a bearing, with the oil preesure being low thats the 1st thing that pops in my head with those shavings