Sherlock: The Riddle of the Crown Jewels (1987) by Bob Bates.
As described on the box:
Travel back in time to Victorian London, where the city is bustling with preparations for Her Majesty's Golden Jubilee. Crowds of sightseers and souvenir vendors fill the streets in eager anticipation of the Jubilee Week events. Newspapers detail the gala array of festivities. Sumptuous receptions for foreign dignitaries. Special services at Westminster Abbey. A Royal Procession through the streets of London. And the Queen reigning over all, resplendent in the Crown Jewels.
At least, that's the official plan. Unbeknownst to the celebrants thronging the city, a crisis has arisen: the Crown Jewels have been stolen from the Tower of London. If they're not recovered before the festivities begin, the theft will be exposed and the government will fall into international disgrace.
Only 48 hours remain to solve the crime. With Scotland Yard failing to make headway, the Prime Minister calls on Sherlock Holmes, the famous consulting detective. But riddles left at the scene of the crime include a direct challenge to Holmes, who suspects a deadly trap. To throw the scoundrel off his guard, Holmes turns the investigation over to you, his trusted cohort, Dr. Watson.
With Holmes by your side, you use your wits, intuition, and myriad of clues to solve the riddles and piece together the mystery. Your search for the jewels and the villain leads you all over London, from the most popular tourist attractions to the seediest back alleys. As Big Ben strikes each successive hour and dangerous complications impede your progress, you realize you're facing that most dastardly of foes, Holmes's archnemesis... the vile Professor Moriarty.