Starting to think its not worth modifying the car to this extent so I can fit into so looking to finish the restoration and then reluctantly sell it."
I sort of support the idea of Where-there's-a-will-there's-a-way and it seems to me that it would be awful to restore the car just to sell it although it could be seen as an investment. Lots of tall people find lots of ways to modify their cars to fit into them.
Here is Norm's effort on his Nagari that is happening at the moment;
The floor is being lowered by a considerable amount. Norm's not exactly of John Wayne's proportions but he wants to be comfortable in the car with his large helmet on.
Here's original "Dinky" owner, Dave Chandler's way of fitting in that car.
Here's another idea.