London Transport's association with Dennis Aces and Maces was entirely peripheral. It only owned four in total (not all at the same time), and all were bought, or ordered, by companies absorbed into the London Transport empire as it expanded in the 1930's. There were also fewer than a handful in non-LT companies within the area. They seem to have been quite satisfactory - and distinctive - little buses, but for London Transport's purposes they suffered from being non-standard, so their lives were short.
The Gravesend Aces, DC1, DC2Gravesend and District was one of the earlier companies to succumb to LT, in October 1933, after the Gravesend Area had been carved up legally between LT and Maidstone and District. The company had ordered a pair of Aces, and London Transport allowed the order to proceed after the takeover. Two Aces with Waveney 20-seater bodies were the result, which duly appeared wearing General fleetnames on their green and black livery. One at least (DC2) went to Guildford for the 448 to Peaslake, while DC1 later appeared at St.Albans. Both only lasted until October 1937, when their duties at Crawley were taken over by Leyland Cubs.
The High Wycombe Mace, DC3The Penn Bus Company at High Wycombe bought a Mace - the forward control version of the Ace - as its No32. It duly came into the London Transport fleet when Penn was taken over in July 1935, and survived as DC3 until May 1939, working quietly away on the 455A at High Wycombe.
The West Kent Ace, No9West Kent Motor Services had a fleet of nine small buses, fourteen or twenty seaters, for use around the narrow lanes of Sevenoaks Weald and the North Downs / Darent Gap. The last acquired was an Ace, in January 1936. The company was taken over by London Transport just after the start of the war, including the buses. Two others were taken into stock, but the Ace was sold without use by LT, its duties being taken over by Cubs from Dunton Green. The Ace went to Newbury & District.
The Windsor AcesWhite Bus Service of Winkfield, near Windsor, who had the distinction of running buses through Windsor Great Park between Windsor Castle and Ascot or Bagshot, had a couple of Aces in the thirties and the war years. Again, the colour scheme is uncertain (the "White" does not refer to the colour) It was possibly red, white and blue.
The Walton-on-Thames AceThe Walton -on-Thames Bus Company was an oddity, in that it was wholy within the LT boundary, yet was allowed to continue. This was because LT considered its operations worthwhile, but uneconomic for LT to provide. In the thirties it operated a small Bedford saloon and a Dennis Ace on a link between town and station. (Operations by the company continued after the war until taken over by Golden Miller in 1970).