Overshoes shoes were quite common in the day.
The drum needs to be at least 0.625" (1/16") oversize for No.1 oversize shoes to fit. The shoes also need to be radiused to suit the drum properly.
Being rear drums I'd have no issue with them being up to 0.080" oversize.
Dr Terry
How far can an oversize brake drum be, before it is deemed U/S .... wait till it cracks?