www.slatersplastikard.com
They have Plasticard sheet in different thicknesses and available in different scales and patterns including brick and roof tiles and of course treadplate the sheet is 12"x 8"/33mm x 20mm the pattern is clearly defined on the smooth side and raised on the other side giving one the choice of which side up you want it to be.
Two downsides They don't accept Pay-Pal and they have a minimum order of £10 but it is a very nice product and I recommend them

I am not sure how useful it would be on a 1/16 Tank body as it is a little too thick but I may give it a try later.