A method I have used where I have also wanted to show the centreline or complete survey on OS maps of various dates is using a drawing programme & importing the maps (I use oldmaps as they are corrected to grid north & scale for pre national grid editions) & googlearth as screen prints. Bear in mind googleearth needs to be corrected from true north to grid north, & can then be scaled to fit to the maps. The survex data can be imported as a DFX file, but will need putting at the right scale & location. This may seem long winded but works for me.
