Karl Bhote in India has alerted me to this advert that has appeared on a Forum there. It was posted by "Ram" and appeared in the Indian Readers Digest of April 1961 It shows clearly the final  assembly of Standard Pennants, called 10's in India.

I am indebted to Ram for this insight into the factory, which is the first I have been able to publish. If anyone else has photos of the Madras production Line I would be glad to receive them, and to post them here.

Phil Homer