Motoring Memories, a haven of automobilia, was first created in 1982 when Robin Barnard, a local farmer, bought the garage and its surrounding buildings in the village of Colyford, Devon.
He has spent the intervening years filling it with rare petrol globes, enamel advertising signs and over 40 petrol pumps.
The garage, built in 1927, was still a working fuelling station until 2001.
Valued at around £750,000, the contents of the museum will be auctioned off with no reserve by South West automobilia expert Richard Edmonds on Saturday, July 13.
More details and a full catalogue will be online closer to the sale.
Tel: 01249 444544.