Unless a serial numbered component is involved, nothing matters.
far as I know (from 28 years in the biz) if i get sent a gun to work on I have to log it if it stays overnight. if someone sends anything but a serial numbered component, nothing matters.
for the shipper; no you dont get a copy of my license. hell, my distributors dont give me a copy of theirs.
You cannot ship a serial numbered component interstate to an unlicensed individual. You can ship as an unlicensed individual, to a dealer in your state or another state for repair, refinish. This applies to serial numbered components.

Brian
LTC, USA Ret.
NRA Patron Member
AHFGCA Life Member
USPSA Life Member