Ah John, after BSF was taken over by Weihrauch they added a few of their own parts and the 55 morphed into the BSF 55 New Model :-
https://www.gunspares.co.uk/products...-55-NEW-MODEL/
After adding a few more Weihrauch parts the BSF 55 New Model became the Weihrauch HW85, which is still in production along with the HW95 which shares the same action.
https://www.gunspares.co.uk/products/24573/HW85/
https://www.gunspares.co.uk/products/24575/HW95/
So in a way the BSF 55 is still with us.
All the best Mick