There will ALWAYS be a risk of cell rot. Are there photos of the razor in cellophane? or is it inside the box and not visible at all?

Often with the fux tortoise shell, you can spot areas of the scales themselves that have changed color, which will surely mean corrosion beneath it.

Many of the razors in Japan are of the Stainless variety. Japan being a very humid place they were common. While severe cell rot can still ruin stainless, it has a much higher chance of survival.

Good luck with it either way if you win it!