Eric,
Allow me to make an observation and a bit of constructive criticism (pun intended) about your beautifully detailed trackwork. You are several hundred spikes too short! What is holding your guard rail in place? One spike every now and then? Now, before the peanut gallery chimes in, let me say this. In your effort to super detail your trackwork, you have inadvertently drawn attention to what isn't there. In this case the unsecured guard rail. The detail of the running rails is top notch, but, the first thing that I noticed, being a former railroader, when viewing your photos there was that lack of spikes on the guard rail. In the real world (and that is what you are trying to portray, eh?) if a car had derailed coming onto the bridge, your guard rail would not have prevented a truck from following the guard rail and staying in line lessening the damage to the bridge. It instead would cause the guard rail to bend out of shape like a piece of spaghetti and cause even more damage.
I would like to address the concept of "Invisability" or "Togetherness". A concept that I am not alone in believing. There are many levels of detail starting from the basic toy train up through the super detailed realistic layouts. For example, have you ever noticed that even on some lessor detailed layouts how everything seems to fit or go together. Nothing really sticks out and it is pleasing to the eye? Then, the modeler decides that he wants to be more realistic and adds a little detail. By doing that, the model is thrown out of balance and he needs to add a detail over here and a detail over there in order to get the scene to balance out again.
Let me try to explain this concept by using two examples of fine railroad art by the artists Howard Fogg and Ted Rose.
First one painting by Howard Fogg. Note the crisp detail throughout the entire painting. Everything is sharp and well focused, nothing out of place. This is one of Howard's distinct traits. And, it all comes together into a very pleasing portrait!
Now, look at this painting by Ted Rose. The image is soft, there is not the fine detail. Yet, the image is all the same and comes together brilliantly in a way that exudes emotion. You can feel the image. It all fits!
Now, tell me what would happen if you were to take Fogg's image of the N&W Y6b and put it instead at the water tank in the Rose painting? Things wouldn't look like they belonged would they.
In our modeling efforts to be as realistic as possible, one needs to decide what level of detail does one want to try and attain? And, keep in mind what one wants to achieve in the appearance of their finished "painting".
"Every tie plate, every scale spike.."
I think that you have a ways to go yet!
Keep up the good work!