Wow, looks like you've done a lot of work already - shame you're not lazy like me and just buy readymade turnouts. Is your roadbed sand/gravel or did you put some cement in the mix - it certainly hasn't lost definition over the years.
Larry... it's all "sand & gravel" or rather DG (decomposed granite) which is much the same, with no cement, so it most certainly has lost some definition as it is more a rounded mound now, but of roughly the same dimensions. Those photos were taken years ago when I first troweled it in, but other than the nice flat top and all the cat, raven, racoon and fox tracks it really is about the same today. Those critters all walk all over my test track as well, but don't seem to disturb it much in the process.