My daughter had the same opinion about the trash level. We spent last week up there, and the shop guys we talked to said they'd appreciate a cleanup as well, but they didn't have the time or responsibility. I thought about bringing my Bobcat skid loader and just running up and down the yard skimming crud, but figured that might be inappropriate.
There are also lots of odd parts piled in new places (for instance, there are a bunch of car platforms -- those bits of metal that bridge the gap between cars -- piled against the end of the station) and they don't add to the "sentimentality" of the railroad.
In any case, we did pick up a bunch of trash while we were there, but didn't really make a dent in the normally visible areas.
I think we may try and put in a day of trash cleanup each time we go out there (so, some day in October, you can hopefully look at a slightly less trashy yard).
Tom