Kuduae-
What you say makes perfect sense. The quality is certainly consistent with FN. I can find no reference to Pieper ever having made Mauser actions. Henri Pieper was one of the founders of FN.

The pear shaped bolt knob looks like a commercial Mauser. Could have been changed. A serial number and German proof mark appear on the bolt handle, 3443, and BV with a crown. The numeral 43 also appears on the extractor, so it seems the entire bolt might be German? The 3443 appears nowhere else on the action.
This photo illustrates the number and proof.

[IMG]http://i85.photobucket.com/albums/k46/mvick2/Mobile%20Uploads/E70BE8FC-1C13-43AB-BD93-B02E4F5A3E60.jpeg[/IMG]

Thoughts?