Massey Harris Pony labeled 820

However, it is fitted with a 4 cylinder Simca petrol engine. 

This suggest that the model is not a 820, because this was made with a Diesel engine. 

The Simca petrol engine was fitted in the models 811, 812 and 840.

The Massey Harris is a small petrol powered tractor. 

It was mainly used in small farms, horticulture and the like. The Massey-Harris was made in Canada, but in the 1950´s a number of Massey-Harris Pony tractors were made in Europe (Marquette-Lez-Lille, France). 

Later is was equipped with a two cylinder Hanomag diesel engine. In some countries it was sold under the name Massey Ferguson 21.

In 1959 it was succeded by the Massey Harris Pony 821. 

Production was from 1957 to 1961. A total of 31277 were made.