Hi,
All the W&W #8's use a 126x1 which is a round shanked needle. There is a 127x1 flat shanked needle which you do not want to use. I'd try the W&W IO group which I'd recommend to anyone with a Wheeler & Wilson. Miller will likely be of great help and is familiar with the #8.
Jon
https://groups.io/g/Wheeler_and_Wilson-Sewing-Machines