And yes....rest your mind at ease. You've got a factory BE date coded, vented gas block upper, that was one of the replacement uppers sold through Arms Unlimited. Given the serial number, it was one of those 50-60 BE/BF that were sold off last year, for about $5K-$6K.
Keep it....shoot it.....and it will never fail you!!! IMHO.....put a RAHG....if you want RAL8000...it's there....or if you want black...it's there too. They are a lot easier on the hands, and the $$$ has come down significantly. Congrats!!!!