GRUMMAN
Grumman's 'Tracker' was originally the S2F, hence became known as the Stoof. Under the revised US aircraft designation scheme, it became the S-2.
Other variants were a COD transport, the TF-1 'Trader' (later the C-1) and a much modified AEW aircraft, the WF-2 'Tracer', the twin-tailed 'Stoof with a Roof' which became the E-1.
The E-1 was superceded by the E-2 'Hawkeye' and the C-1 by the C-2 'Greyhound'. Finally, in 1975, the S-2 was superceded in the ASW role by the Lockheed S-3 'Viking'. An ELINT version, the ES-3A, was known as the 'Shadow' which replaced the venerable EA-3B 'Skywarrior', a handful of which were still serving in Gulf War One.
The image in the parliamentary document shows an E-2.