Apologies if this is too off-topic or in the wrong forum....
The link below leads to video footage shot from the front of a train as it leaves the Royal Albert Bridge (east-bound) and heads into the Plymouth suburbs, shot in 1901. It's a pretty fascinating if brief insight, with a few particular highlights such as the trams, construction of the Camel's Head bridge and the total lack of housing and other buildings!
Despite it's title the film does not start at St Germans nor finish at Millbay - if it did (presumably these sections were destroyed) it would include the original course of the
GWR▸ between St Germans and Wearde and would be an absolute gem of a find!
Nevertheless it's still a great piece of historical footage:
http://player.bfi.org.uk/film/watch-beautiful-panorama-of-railway-ride-from-st-germans-to-millbay-1901/