Rocketman, are you English?You talk far too much sense to be domiciled in the Colonies.
In this weeks edition of Shooting Times John Knibbs formerly of BSA writes an article about the Birmingham Gun Trade.
"Fifty years ago the Birmingham Gun Trade Registry listed a total of only 30 master gunmakers, of whom just 20 made guns under their own name, others in the registry branched out into gun related activities"
"A current check of members of the Birmingham Trade Registry lists 44 active gunmakers or companies, the highest number for 100 years".
Right now settle down and let me give you a little history lesson.
London is the home of the self proclaimed 'Best' gunmakers.
Birmingham is the home of the workshop to the World.
W.W.Greener who possibly did more for gunmaking than even Joe Manton based his workshops in Birmingam, so did Westley Richards, & WC Scott who between them shaped what we all use and love and cherish today.
So lets end the myth that only London produced a quality shotgun once and for all.
Anyone who doubts this should have a look at a current Purdey or H&H then go to Birmingham and look at a current Greener or A.A.Brown.
Getting back to the original question of this thread about in house manufacture.
A current Greener although made wholly by Greener the components are all crafted by individual craftsmen specialising in different aspects of the gun in different workshops until final assembly where it becomes the responsibility of the finisher to pass off all quality issues.