You lift the carpet to find that the drivers floor pan where the chassis number is has disintigrated with rust?? Or partially disintigrated?

Do you plate over the bottome so that anyone looking from teh top can see that the numbers have not been cut out or ringed over, just that they have rotted away?? or do you put a floor pan in and stamp the numbers back in??/

future buyers might be put of aswell - just wondering how to get round it cos i had a few cars like that, but luckily i wasnt putting them back on the road.

P.S - apologies if this has been posted in teh wrong section!