I had hoped to get a sheet of MDF cut but time was against us - which was just as well as I discovered a 5ft by 3ft in the shed! All it needs is painting and grinding and will then be real to use. In the meantime though I could always grid the cloth I have or could even - and this came to me yesterday afternoon - use Barry Carter's rules without a grid and merely use multiples of 3" for movement and firing. I would need to add in some turning rules but I reckon this has some mileage in it especially as it would serve to open the table up for more manoeuvring.
I was able to finish the four ship models I will be using for the Denmark Strait refight so without further ado here are the stars.