Date of photo above is unknown, nor do we know if the marker pictured is an original cast iron one.
Greenville, MERCER COUNTY
Similar double-sided markers were found at most state-affiliated colleges. In most cases, if such markers are still there they are replacements of the original cast iron ones. We are not sure if these were a part of the PDH marker program or were a separate program by/for the colleges.
A 2017 search failed to find this marker, so it must be assumed it is long gone.