Overwritten can mean:
new files taking their places, so they are gone.
only "this place is free and usable"
then you have a chance.
(You never now if the new files are on the same place physically....)
Anyway: when youre not sure, let one of the recommended porgrams look for them.
1D MKIV, 1DX MkII, 5D Mk IV; lot of lenses, flashes etc
Fuji X100s, Sony RX100 III,
Fuji X- XT1, X- Pro2, XF 23 1,4, XF 18- 55 2,8-4, X- T1, XF 16/1,4, XF 55- 200, XF 56/1,2, XF 50-140, XF 100- 400