this is common practice in pakistan and india that people sell guns ion this way.
in pakistan we have bigesst open market of firearms "dara adem khel " where skilled craftmen do some thing more.
they are expert engravers as well beside making fake hollands and purdeys they do the worst thing by changing the identy of other english makes and fine european makes into well known makes.
beside this they reuined lot of double rifles by converting them in shotguns.
i saved one fine piece of r b rhoha 500 no 2 from such fate last year and daily i encounter many such guns.