Another good point to consider Tim H regarding the vibration absorption, thanks for that.
To clarify I wasn't after change for change sake. The timbers are original so 50 years old and to be fair still look to be in usable condition.
I was thinking that as the car is stripped down to the bare chassis it would be wise to replace them. If during the last 50 years another presumably better material has been discovered/invented I would adopt that. I am guessing that a big consideration in Morgans choice of using wooden planks in the first place would be cost rather than it being the most suitable material.
