UPDATE: thanks to foreign comrades, I now have additional details and have added them to this article.
Digging in British Imperial War Museum website I found this very pretty photo of a clearly experimental vehicle.
In the note to the photo it says that this is an”unidentified Vickers armored car”. I also did not know anything and did not see any mention of anything like that. The museum’s website, claims that this photo was taken in the First World War period, but this is wrong
In fact, the photo shows a prototype of a wheel-cum-track tank built in 1927 on the basis of the Wolseley-Vickers wheel-cum-track car, which was built in 1926 on the basis of standard Wolseley car.
In the photo you can see a fairly common for the post-war time wheel-cum-track idea of combining wheel and caterpillar drives with the ability to switch from one to another, obviously for maximum mobility both on roads and off-road. Visually and conceptually looks like the KH-50 tank, developed in the first half of the 1920s.
It can be assumed that the British wanted to create some kind of intermediate link between armored cars and tanks, which can take advantage of fast movement on ordinary roads and go to a crawler drive to overcome the WWI-style battlefield (what was expected in the future war).
Crew – 4 people. The armament was to consist of 3 Vickers machine guns, but only one dummy machine gun is visible in the photo. Speed on the road was about 25 miles per hour and 15 miles per hour on tracks.