Gould anyone help me source a screwback for my sons watch unbelievable as it seems hes lost it I've searched the internet to no avail thanks Tracey

 

You'll need to post good pictures front and back. There were very many different models housing the 354, some very similar to each other.

 

I suggest you pm @seekingseaquest who knows as much, if not more, about 50s bumpers than anyone else I’ve come across recently.

 

What he said. Unfortunately some of the easiest identification of these is from the outside of the case back..