Morning Eilleen
15, 17, 19 St Martins Street ... 1, 2, 3, 4 St Martins Hill ... 20, 18, 16, 14 etc St Martins Street
so it looks like it was somewhere at the top of St Martins Street. It's not marked on my 1883 map of Lincoln (when St Martin's St was marked as Drapery)