The Hong Kong Railway Society gives us the background:
1936, Hall-Scott Motor Coach No.1 was totally rebuilt and refurbished as a 1st Class lounge & observation car, which included a separate cocktail bar and smoking lounge. The interior was lined with French polished teak wood and to complete the luxury deep-padded armchair type seats were fitted. The exterior was finished in a blue and silver livery. The coach, which was named the “Taipo Belle”, proved particularly popular with weekend golfers on their way to Fanling golf course.
On 14 October the Taipo Belle made a record breaking run to Canton in only 2 hours 15 minutes which compares very favourably with today’s through train services. At the end of the year the other motor coach was given a similar facelift but on this occasion the newly named “Canton Belle” was finished in a dark green and silver livery, entering service in 1937.
It looks like something Flash Gordon would have felt right at home in.