Seems to me this would have to been before any prototype. If there was a prototype why wouldn't he used a real picture of an ASAT Classic. The picture is clearly an ASAT. It has the Locktight (Saddlelock) bridge. Someone has drawn in the ash tray by hand, you can still see the pickguard undwr the pencil shading. The dark lines outlining the ash tray are wavy from being hand drawn. Even the headstock is hand drawn.
I thought the all hand drawn picture was much more interesting specimen of the three sheets.
It's obviously a combination of the saddle lock and box steel bridges but what would be the advantage of that? Seriously has anyone ever seen a guitar like this that is real? It looks like a fake to me.
This was not done prior to the invention of the saddle lock so why combine the two. Maybe just a fanciful idea that made no sense so went no further?