Dear UFR131
Below is the answer from Robin Woolmer when I asked the same question 2 years ago
Basically use the old type of antifreeze and nothing modern including Evans and any water free ones
The VSCC members believe that the original grade of Bluecol is the best for pre war & historic engines including Aluminium, I am about to purchase some myself & the recommended grade is BLA005 (5 litre tub), you can look it up on there web site '
www.bluecol.co.uk '
There was a great deal of dialogue on the VSCC Forum also considering the ' Evans' offering which was not at all recommended.
Regards
Mike Smith