After searching YouTube for some drone footage of Bangkok, I came across this old video that was reportedly taken around 1931.
This is some great footage that includes The Grand Palace and Wat Arun back before most of us were born. Also there is some short footage of the klongs and the railway system but exactly where this was shot I cant say.
If anyone can shed more light on where this footage was shot please send us an email, firstname.lastname@example.org
Original Video: http://youtu.be/fk1jDN9fk7Q