While I generally consider 'bobbing' and 'chopping' pre-1980 xs650's to be a bad idea, that 'Panhead' one looks more ride-able than most of the bobbers I see on this forum. It has a spring seat, nice big fenders, mufflers, windshield, saddlebags, front brake, decent handlebars and riding position, etc. I wouldn't want it, but at least he thought about it and built something unique that you could actually ride.
As for the first link, its amazing that all you need to build a 'brat style' bike is a can of black spray paint and a hack saw...