From the look of the Matilda II photos on the WLG website, it doesn't seem to have any options...
https://store.warlordgames.com/products/matilda-ii-troopMajor variants for the A12 Matilda II:
Infantry Tank Mark II (Matilda II)
First production model armed with a Vickers machine gun.
Infantry Tank Mark IIA (Matilda II Mk II)
Vickers machine gun replaced by Besa machine gun. The "A" denoted a change in armament.
Infantry Tank Mark IIA* (Matilda II Mk III)
New Leyland diesel engine used in place of AEC engines.
Infantry Tank Mark II (Matilda II Mk IV)
With improved engines, rigid mounting and no turret lamp.
Matilda II Mk IV Close Support (CS)
Variant with QF 3in (76mm) howitzer, firing high explosive or smoke shells. In British service, these were generally used by HQ units (usually a single command vehicle), whereas entire Australian squadrons often appear to have used them – frequently in a direct fire role, against Japanese strong points.
Infantry Tank Mark II (Matilda II Mk V)
Improved gearbox. Westinghouse air servo used.