Farmers are not an easily impressed bunch. But walking into the warehouse in northern Geelong, even the hardiest pastoralist would have been awe-struck.

A never-before-seen collection of rare and vintage tractors has been opened up to the public before being sold at auction this Sunday.

Bruce Chapman casts his eye over a Massey-Harris tractor. Credit:Jason South

More than 100 restored tractors will go under the hammer, spanning a string of different marques and models from 1919 to 1980. The total collection is valued at $1 million.

But the thing that has all of the tractor fanciers baffled is this – how did no one know about it?