It’s a broken E500, the brass mechanism in p2 cracked.
6(in the middle ‘auto knock’ part) +2(in the front chunk) tiny metal balls are not shown in these photos. Those 6 balls are shown in another post mentioned below.
Besides, one part here has a brass shell, while another disassembly posted earlier in this forum, that part looks like it is made of a different material: Pilot Automac E500 - #7 by tfhs
