I have a Premier King handlamp. The only number I can see on it is R123 on the top of the clamp, plus the brass plate on the back.
If you would like some photos or indeed, want to borrow the lamp, please pm me.
Where there's a mine or a hole in the ground.
That's where I'm heading for that's where I'm bound
So follow me down Cousin Jack
(Grateful thanks to Show of Hands)