Can anyone point me to images of a Mk IV Sunderland please? Interested in the armament so needs to be close and/or good definition. This model had only 8 built plus a prototype as the Mk V came out almost immediately. The Mk IV was up-gunned and it is details of the guns I am after. I'd also be interested in any shots of other versions with .50 calibre Brownings or 20mm cannons or anything else up from .303. Thanks.