I was looking for information about two aviation charts that I acquired at a book fare recently and saw your post. These may answer your question - at least in part. The charts were created by Stanford, which is a long established map and travel specialist based in London. There is a reference date 1934. It appears that the charts were custom made using existing maps cut down to fit into a concertina map book. The courses and distances between major cities/ transit points have been inked in and information about airports, compass roses, and the key have been pasted in, and then varnished.
I am sure that they will have been made for the first two legs of the Imperial Airways route (London, Croydon to Athens and Athens to Baghdad) to Australia, where regular services were established in 1934, although whether these particular maps saw the inside of a plane, I am not as sure as they are in excellent condition.
I tried to attach some photos, but the site said I cannot use URLs until I have posted 8 times, so I have used quick reply. I have not used any URLs, so I don't understand why I was blocked. I am happy to send you the photos another way.