Mysterious chips in the oil

[Ford-A-baquet]

greetings from lake constance
Rebuilt my engine with modern main shells, new rods, pistons, oil pump, B-cam, pump drivegear. Filled the 5 liter engine oil and pressed the starter button. When the oil reached the chamber to the right I stopped and mounted the valve cover. For pumping the oil to the last chamber to the left, I pressed the button again. This morning I was curious and turned the crank with the Ratched nut wrench. The engine can be easily turned but in one position I noticed a slight rattling. Unscrewed the valve cover and found the chippings. They are not magnetic. For my understanding only possible chippings from the middle shell from the cam or unidentified chippings from the oil pump.
The engine turned maximum with the starter and in my opinion it`s not something picked up from the oil pan. So many chippings in this short time from the pan not possible. What is your opinion.
Regards Rik