Hi bertus / Oscar & Jim K.
I was finally able to do a little more research, & this is what I have found.
From Gun Makers 1350-1850 By Howard L Blackmore, Manton supplement by Neal & Back 1849 volume. "Geo.Henry Manton favored quality shotguns, while Gildon Manton favored volume production, so was some of the internal affairs, which started the Indian Colonial market.
Guns by Frederick Wilkeinson pg 150.
In the eighteenth century Manton's & most of the British guns were produced in Birmingham and the parts sent to London for finishing and assembling. Clients prepared to pay the price could still have the entire gun made in the shop in London, by the London maker.
Antique Guns & the Collors Guide by John E. Traister, pg 174.
It was only after 1893 that H.D.Folsum, Bacon, & Cresent Firearms were now producing a vast number of firearms under a host of names of about a hundred such makers, which included Barker,CW Franklin, Manton, W.Richards & Wilkinson Arms Co.
Belgium made gun parts proofed in Birmingham were also marked with a Crown & F for foreigners.
In view of all of this I feel confident that this shotgun is a Manton & not a Belgium knockoff. The master himself may not have laid his hands on it but it is real & genuine, & I accept this.
My daughter is tickled pink to own it now.
Thanks to all, for your input while the research was on going.
Digger.