Frank Greasley found these handcuffs when clearing a house approximately 40 years ago. They are similar to others currently in the museum at Oakham, Leicestershire. There is no key. They are locked. IF the relevant sized socket key was available they could possibly be opened.
At each rounded end of the handcuffs there are some numbers - they are not very clear. One end has numbers that look like 602 and a number 2 underneath. The other end has 2771 with 1 underneath.