Hi Colin
I think that you will need WM2 19 x 3.25 rims with 40 spokes per wheel. I have a 1932 350 cc A32 which is not too different from the EW. A good supplier is C. Wylde & Sons Tel: 0113 246 8888. and talk to Bob Wylde. The rear wheel may need a different rim - Italian - if the hub is narrow with a tapered spline for the brake drum and sprocket.
As you are in Guildford, you could pop up to me in Lightwater and see what has been done on my A 32. My phone number is 01276 471921.
Cheers
Paul Douglas Goodenough