Hi,
First, my thanks to Jon who sent me the link to those great photos. They didn't answer my questions directly but certainly provided motivation.
I am now a little deeper into the bridge build and though I would provide a couple of "heads ups" regarding my adventures.
As I get into the build I find the repetition not as odious as at first expected. I made a couple of simple jigs to help the operation along and have finished the 12 main segments as seen on p. 3, left side, wiht the exception of leaving parts I 13 until I actually start assembling the bridge. I don't think you can slide the girders into place if you have already glued parts I 13.
The jigs are just matte board , one to make sure the main structure of each segment unit is square (top picture on p. 3) and the second is to make the angle of the diagonal braces consistent. ( The angle is greater than 90 degrees, by the way.)
The instructions don't mention that it is critical that parts I 11 (which do not have any positive placement guidance) are located exactly to match the pegs on parts I 4 AND each of the 12 bridge sections or you will not be able to attach the sections together later in the build.
This is a far as I have gotten so far. If I make any other discoveries of hidden hitches in the build, I will communicate them.
Mike