The accident happened "exactly" 152 feet east of that milepost. So if the sign is not at that location it is not "exactly" correct.
I measured it off years ago with a tape measure and thought it was pretty cool to be standing at the exact spot where the rails were washed out.
It is interesting to note that the cap on the top of the milepost that is missing was stolen as you would suspect. The person who took it placed it in their back yard in Marlton. Unfortunately for him he was not able to get the bottom tubular metal portion of the true milepost 86 out of there so he stole a different one and used that. Nobody would be the wiser except he sent me a photo of it and obviously we know that I am correct. So if you ever see it on eBay (which I doubt will happen) ask for a lower price.