Standard post (sign) documents define the sign and describe how to place a post in reference to the track. The other question you asked related to locations of posts/signs and Jim Gross noted that the Interstate Commerce Commission' valuation maps provide a record of historic locations for D&RG signs along what is now the ROW of the C&TS. The Colorado Railroad Museum has put together all the maps for Antonito to Chama in a 12in by 30in format. I understand that some things can be ordered remotely from the museum but that others may have to be purchased at the museum.