As I wrote before, it's true that this is a component part of a firearm, but so is a grip-screw or sight.
What it is NOT is a pressure-bearing component of a firearm, just like a grip-screw or sight.
I'd like to see the source of the information given you by your FEO - personally I think it's BS.
I've bought wedges for BP revolvers from Dixie Gun Works without causing an international incident.
tac