A friend of mine sent me a a really charming old film on Ceylon. It is a travel documentary and was made in 1931. A quick search revealed a couple more. You can view them at the links below.
Charming Ceylon 1931
Tropical Ceylon 1932
1960s cine home movie featuring Ceylon and Singapore
Also a montage of old postcards on Ceylon is available here
Youtube never ceases to amaze.
Another old film that I have been looking for is Basil Wright's Song of Ceylon, made in 1934 for the Ceylon Tea Marketing Board. Interestingly the narrator is Lionel Wendt. At one time it was considered to one of the top ten greatest films ever.
Details (but unfortunately no clips) of the film are available here and here.
If anyone else knowns where to find old films on Ceylon please let me know.