Is there anything unusual about 50012? I am asking because I have 50071 which is an EL320 made on an early ES340 (pre-N) action, or an single shot MM410 (pre-N), or an EM330. I also have 50439 which is an EL320 made on an later ES340 (pre-N) action, or an single shot MM410 (pre-N), or an EM330. Could it be that the 50K serial numbers were used for custom special orders?