Sibwings' model I think - before they became famous. It's still the first (Fs8 or 9) model.
This plane really begs the OrbX Redux treatment and/or a new mdl. Another thing I discovered this morning (and I was on the FSX beta test - for SHAME on me!!!) each different version has slight variations so that you actuall need more than one paintkit. On the wheelie ones, for instance, the fuselage sides, top and bottoms match differently to the floaty ones. And apart from the gloss being regulated by the spec alpha annd not the diffuse alpha and the bumps being so grainy and the stbd wing strut not bolted on to the fuselage and the door stiffener bulges "floating" and the floats being phototextures...
...it's still a lovely plane!