This is not all correct. If the buyer can't read/write or is blind, then you can have a third party fill out the form (except for the signature) and you ALSO NEED two more witnesses that also need to sign the form. ATF put out a letter awhile back allowing common abbreviations to be used, ie GA...
The top cover has been welded up to keep it tight on the receiver. The AR stock adapter is an ACE unit, distributed by J&T. The gun has the optional SRTrigger installed.
Burris 8-32 Black Diamond. Probably not the best choice for a 50, but it's what I had laying around at the time.