Ah, there is An 6 there which I read as an zero, but still 6 pixels too big?
I dunno, if I scale that drawing to 30 pixels high, the total width ends up as... 70 pixels.
Frankly I went over that cannon, and so did Mitch, and as much as I am glad he's gone, at the end of the day neither of us could find much to improve on it, and we scaled mostly off photographs. I think that drawing is fuxxored.