You can spend many hours browsing round the old Ordnance Survey maps of London and elsewhere that the National Library of Scotland has made available, free of charge.
A feature of the 1893 map is that it includes some archaeological information, along with contemporary street plans. According to this map, a stone coffin was found in Deptford's Nelson Street, now Vanguard Street, in 1868.
A local Oxford Archaeological Unit survey, conducted in 2006 in relation to Reginald Square, has a bit more information about it:
'The line of Roman Watling Street, the road from Dover to London, is believed to have crossed the River Ravensbourne at Deptford and then followed the modern Deptford Broadway... The Dover Castle Inn excavations found evidence for Roman occupation on the north side of Deptford Broadway... A Roman building with a tesselated floor was found near the corner of Deptford Broadway and Deptford High Street during sewerage work in 1886... A probable Roman stone coffin was found in Vanguard Street, south of Deptford Broadway.. in 1868'.
