In Geofrey Higgins 1826 book The Celtic Druid there is a drawing of a plan of Abiri and parts adjacent which clearly shows Silbaby with the words "Barrow cut through by the Romans.
Also,
Topographical sketches of North Wiltshire by John Britton, 1826. p306
"This shows Silbury hill was ancienter than the Roman road. The makers of the same Roman road cut through another barrow, of smaller dimensions, east of Silbury hill."
http://www.wiltshire.gov.uk/community/gettextimage.php?book_no=049&chapter_no=13&page_no=0043&dir=next
Is this enough for TMA ED's to take Silbaby off the Disputed Antiquity list?
PeteG