Looking at the off-kilter decoration on the sideplates I'd guess this is a workin' man's gun, maybe a Belgian export. (No disrespect intended.) Look for proof marks under the breeches.
There appears to be a ramp milled between the extractor channels in pic #7. Some sort of a finger might rest at the bottom of it as the gun is fired, then as you lower the barrels the finger could push the extractors up and out. The finger wouldn't have to move to do that. But a spring would need to be compressed and a latch tripped to pop the finger back in place, carrying the extractors back. Pics of the forend iron would help.