My apologies for the delay, I now have an answer from the factory.
The product is Dinitrol Black Wax 4941 - I have attached the Technical Data sheet to this post for members to download, should they wish to.
Morgan Motor Company used to use Dinitrol clear wax but it seems the feedback from customers was that they preferred Black Wax and therefore the company moved over to using 4941.
Hope that helps.
