My mum's old Singer 457 (circa 1971) treadle (part no: 102949)?

Hello Ruth,
On the bottom of the pedal there is a rubber mat, peal off the rubber mat, it may break into pieces due to it's age, the screw that needs to be undone is in the middle, the surrounding bakerlight might break away in one piece once again due to it's age but it can be glued back, unscrew it all the way to open it.
Ken

ken
November 2011