This is the British specification version of the Whites M3A1. With the spare wheel and extra fuel cans carried externally this vehicle could carry a crew of 8 people and be armed with 3 heavy machine guns (2 x 0.30mm and 1 x 0.50mm).
The Guernsey Military Vehicle Group is affiliated with the UK Military Vehicle Trust (MVT) (http://www.mvt.org.uk/), which is a nation-wide society concerning the conservation of military vehicles.