I appreciate the advice David.
However, I had that MFT top made about 3 years ago and it still has plenty of life left in it as yet.
The lower face is unmarked, so I can always use it that way around when the upper surface gets beyond practical use.
Plus the fact that i do consider it a consumable item as i could always just have another one made once this one gets beyond economical use ( I'm fortunate to have a good friend with a large CNC machine...) The major initial cost of this one was the time it took to write the CNC programme.....To have another one made would be far less but obviously, still allowing for the cost of a sheet of 18mm MRMDF.