Trainers size 7 may fit in size 6 comfortable type (CT13)

Trainers size 7 may fit in size 6 comfortable type as need to cycle possibly to a job in them soon used to fit in size 6 but these days it's like they have all shrunk, ones I've been picking up in charity shops when lucky enough to see them at reasonable price, so may need a 7, but if big 6 may fit, so if you have either to give I'd be most thankful