Much of that assistance has been mentioned here before, including Jack's invaluable help with route design and operations planning, Rich's help with paperwork and locomotive manipulations, and Nick's help with signal design and construction. Those are all cornerstones of the model railroad. For some of the details, Al T. has been quietly contributing since he has first been part of the crew.
In fact, so quiet have the contributions been that the operating crew now looks forward to seeing what might pop up next. At one operating session, we suddenly found 'blue flags' for protection of standing equipment, used on the prototype to protect employees working on standing equipment.
For locomotives in Onondaga Engine Terminal like U23B 2795 here, blue flags now protect mechanical department employees who may be servicing locomotives. Before moving equipment with a blue flag, the engineer must use the radio to make sure crews are clear of the equipment.
Another sudden arrival was a full set of the classic New York Central concrete milepost markers, nicely represented in HO scale and appropriately placed around the railroad at just the spots I would have placed them - but Al got to it first! This sort of assistance really adds to the prototype feel of the layout, even before scenery is started.
At one session, out of the blue, a talking defect detector began to announce the safe passage of trains through Camillus, NY, over the radio - Al had put together a quick recording that sounded much like the Conrail voices sounded, and using his radio for one session, we had those sounds on the air.
Then, this past winter, Al was operating a train over the railroad and called the dispatcher to report some 'kids near the tracks.' Turns out those kids were trying to light up the approach-lit signals with some copper cable to check if any trains were coming. Jack and I can't imagine where Al got that idea. Thankfully, there were no further issues.
These sorts of details bring a layout to life, even one that has yet to see any significant scenery construction. Model railroading is a social hobby, and the Onondaga Cutoff is better for it!