by rphillips52 » 5 Nov 2020 15:17
These are normally 1 or 2 levers. If in working order, and not full of fluff etc., it should need the key to lock, otherwise pressing the button (that one does not look like one that slides) should release it.
As mentioned, releasing the rivets is another method. Replacing this with a similar lock might now be difficult; the OP might prefer to keep the lock and put it into working order.