Best of an 18-lot specialist section at the spring sale was their latest 'barn discovery' - this 1932 Marendaz Special sports 2/4 seater, right, only around 30 or 40 examples of which are known.
What added to the unregistered vehicle's immense appeal to enthusiasts was its original condition. It had been stored in a dry barn since at least 1947.
"Its seats were original, its carpets were original, even its canvas hood was original," said Adam Schoon.
Its only visible defect was a cracked aluminium valve cover. A UK collector outbid rival enthusiasts emerging triumphant at £31,000. The buyer plans to spend about £50,000 to fully restore it to its former glory.
Another vintage car roars out of a barn at £31,000
The Yorkshire Dales, have proved a happy hunting ground for Tennants when it comes to selling classic cars and motorbikes.