OK here's a question more aimed at our Japanese members. 3 years ago I renovated my low kilometer Japanese domestic market Katana 750. When I painted the frame I noticed how light it felt, I had a CB750K2 frame being painted at the same time and I know they are completely different but none the less similar in size, the Kat frame felt half the weight of the Honda. Fast forward to now and I have an Australian delivered Kat. 750 frame and I'll guarantee it's a lot heavier than the one I did previously. Does anyone know(no guess's please) if the Japanese models were made from different metal? I cannot believe that smaller wall construction would make that much difference. When the latest one's together I could take the tanks off and run them across some scales. Any clues!