You are probably all aware of the infamous Bob Semple tank, from New Zealand. They were described in the Evening Post as "Powerful machines". When first introduced to the public in March 1941 this is what the newspaper had to say:
This attempt at public relations soon failed as the public caught their first glimpse of the Bob Semple. It was an ungainly machine lashed together with whatever materials could be sourced for its armour. The rapid firing guns were nothing more than machine guns.
The news story however highlights another interesting thing, the Bob Semple wasn't the first of its kind. The article in the news starts out:
"The genesis of these 25-ton tanks was a photograph taken in the United States and given to Mr. Semple."
Now one can't be sure,but I think we can make an educated guess as to what that photograph was of. I believe it may have been a Disston Tractor Tank. However there is, as always, conflicting information on the subject. Originally designed during the Great Depression, lots of companies were considering how to sell to the world when everyone was in a bad way financially. Sources differ, some say it was the Caterpillar company, others that it was Disston themselves that came up with the idea, however the result was a Caterpillar model 35 tractor with with an armoured body made by Disston, a company well known for quality steel products, with an emphasis on safes.
Armament in both cases seems to have been a 37mm M1916 infantry gun (very similar to the gun of the FT17). Along with that the Disston had at least one .30 Calibre machine gun.
By 1935 the worst ravages of the Great Depression were receding, and the Disston company had to alter their marketing. They now pitched their tank as something that could be assembled in under two hours, implying that it didn't need to remain as a front line vehicle. Again this seems to have been aimed at less affluent countries. One order was placed by China, although the order seems to have been cancelled in 1935. In the same year the first deliveries were made to Afghanistan. The exact number delivered isn't known, but at least five can be identified in photographs. Some sources suggest completed tanks and a smaller number tank bodies were delivered.
Wikipedia page on the subject and you can make your own mind up.
What is certain is there are a large number of photographs of Soviet tractor tanks, of different models. So its likely that some did see combat to some degree.