Story of the famous Agra Diamond of India -fiction or fact

Famous Agra diamond
During the hey days  of its influence in the world of spices, sugar and  textiles, India was known as the the capital of gems and stones in the entire  British Empire and it was the primary  source of many famous diamonds,  majority of which eventually made their way to Britain either as gifts or stolen. There were famous diamond mines near Hyderabad (now one of the world IT centers), called Kollur or Golconda mines and near Panna in Madhya Pradesh. Panna diamond mines  are not very active now. Golconda mines became inactive long ago.  

In 1526, Babur, the first Mogul emperor, in a decisive battle against the  Gwalior Rajah, conquered the city of Agra, the ultimate home of the the famous Taj Mahal. His son spared the lives of the incumbent Rajah and his family, and was given the Agra diamond among a cache of jewels as a token of gratitude.

The famous pink diamond changed hands many times as India came under many rulers in  quick succession. During the British rule in 1857,  there was a wide spread rebellion against the autocratic rule of the British India company. In the midst of the worst rioting,  a young British soldier.
stole this Agra diamond  from the ruler of Delhi.

The  British military officers  made up their mind to smuggle it into England and share the sale proceeds. They hatched a plan and their modus operandi was  almost similar to that of the legend of Trojan horse. The main difference is the British Bobs used an ordinarily  'live critter'- horse. They hid the diamond in some horse feed, had a horse eat it and then ship it back to Britain. The plan worked well, until the regiment reached the port where they were to board ship, but in the middle, their plan went haywire. The unfortunate horse, having taken ill, had to be shot. They removed the diamond from the dead critter's stomach and took it to England, where it was eventually sold to Edwin Streeter, a famous London jeweler.

Edwin Streeter purchased the Agra diamond in 1891
The marble wonder Taj at Agra,India.
Is it a true story of the great Agra diamond based on facts or fiction? some aspects of this story, particularly the dates when these events were said to have taken place, need scrutiny. Proven documents show that the Agra diamond was purchased on November 8th of 1844 by Charles, Duke of Brunswick, from Blogg & Martin,a well-known firm of diamond merchants in London at that time. A note in the  sales display catalog  specifically mentions the diamond as having been  taken by Babur in Agra in 1526.
 One  possible explanation for this discrepancy in the story  is that, the diamond purportedly eaten by the horse, was not the same stone. The other sources that support the story  have stated that the smuggled stone in 1857 weighed 46 carats rather than 41 carats.

In 1899 in Paris, the Agra diamond was cut down to 31.41 carats by the jeweler Bram Hertz, from whom  Edwin Streeter purchased the Agra diamond in 1891.

Having changed many hands the Agra diamond was put up for sale at Christie's in London on June 20th, 1990, by a seller who had inherited it in 1927. After fierce bidding it was sold for £4,070,000; well over twice its expected value, to the SIBA Corporation of Hong Kong.