According to “Vulcan from a Different angle” by Craig Bulman (a great book for finding what mod happened to what aircraft when) of the 34 blue steel vulcans those still around are;
XL318 (Hendon), XL319 (NEAM), XL360 (Coventry), XL361 (Goose bay), XL426 (Southend), XM575 (East Midlands) and XM594 (Newark).
Apparently not all of these had two counterpoise plates (XL426 didn’t).