After driving through the night with his truckload of apples, a very tired Nick arrives at the market and seeks out Mike Figlia at his corner business, at the southeast corner of the Washington and Davis intersection, the center of activities of San Francisco's Produce Market (location 1 on this map).
Then ... Mike Figlia's was at 364 Davis Street, but the signage was created for the movie.
... in the 1950s ... the vintage photograph below shows us the name of the real business at this location, the Half Moon Fruit and Produce Company.
... and Now, could this be the same location? Yes it is, looking south down Davis from Washington. The entire block, of which this building was a part, is now a park.