They're by a company called 'Apple to Pears', bought from Amazon; sorry, should have said so, £16.54
I had something similar, but with a plastic handle from the same company, but I seem to have lost them on the allotment somewhere recently, one of those things you put down and then you can't remember where you put it down, I expect they will turn up when I am digging everything over in Autumn. Damn nuisance losing them as folding secateurs are really convenient to just stick in your pocket for all those pruning jobs.