Vincent Formosa

I've seen a few photos of desert Blenheim's with a 20mm cannon in the nose. it's mounted on the right hand side of the nose and points through the clear view panel. the underside guns have been removed and the pitot has been moved. does anyone have any photos of how the cannon was mounted inside the nose? or can point to an account of being used for ground attack in the desert? also, anything regards 2x 20mm cannon in the nose? if not, was it a weight issue, ie having 2x 20mm cannon upfront upset the centre of gravity. hence why only 1x 20mm was fitted. can anyone shed some light?