You may have gone from Lincoln via the "New line" through Tumby Woodside etc, and joined the East Lincs south of Firsby at Little Steeping, then changed at Firsby from a Skegness train into something from Boston (or Nottingham etc.?) which was going on to Mablethorpe.Looking at the bottom photo on p713 of December Steam Days, the one of 61159 on 11 July 1956 taken from the Locomotive Street pedestrian bridge shows how immaculately the track was kept in that period even on a secondary route likje the East Lincs. Then however, BR employed staff in the Engineer's Dept known as scavengers whose job it was to dispose of any rubbish and left over materials remaining on the right of way. No chance of vandalism causing derailments then. The did away with scavengers to save money, so many years later we had Hatfield etc.etc.