The Osprey book 'American Spitfire Aces of World War 2' says Fields was killed flying Spitfire IX ER130 near Anzio. Problem is ER130 was a Mk V, although some Mk Vs were converted to Mk IXs I can't find any evidence that ER130 was. Keep in mind it's an Osprey book so although they are generally accurate you should take it with a grain...
The broad chord rudder was used on a lot of other Spits including XIIs, IXs, and XVIs, in fact the early Mk VIIIs entered service with the standard chord rudder, the big VIII give away would be the open tail wheel doors catching the light below the H stab.