This scene, where Harold stops by the studio of Maude's artist friend Glaucus, was filmed in the former Southern Pacific Rail Yard alongside Bayshore Blvd in the City of Brisbane (map) at a building that has since been demolished. CitySleuth thanks Walter Boland, whose father worked at the facility, and Chris Hart of sanfranciscotrains.org for their help in identifying the location.
Then ... He approaches the building, evidently a tall one; the view behind him looks across Bayshore Blvd and past the PG&E Martin Substation to the hills beyond.
... and Now, from approximately the same spot. The site, like most of the abandoned 200 acre rail yard, is now an expanse of weeds.
But which building was used to film the studio scene? In this 1946 aerial photo it's the long narrow building on the left; the arrow traces Harold's approach 25 years later in the Then image above. The building , the Erecting and Machine Shops, was known by the employees as 'The Backshops'. It housed a row of stalls used for working on steam locomotives. At far right is the circular Roundhouse with its 40 maintenance stalls, 17 covered and 23 uncovered, and a turntable at its focal point.
... and Now, a recent Google aerial view reveals that the backshops are gone, leaving tell-tale hints of where they used to be - the arrow points to the corner of the building where the entrance to Glaucus's studio was. The covered part of the Roundhouse is still there, despite damage by fire in 2001. The surviving building at the center of the image used to be the Tank and Boiler Shop - it's now the home of Lazzari Fuel Co.
Then ... He opens the door to see artist's paraphernalia scattered around a huge block of ice.
As mentioned, the backshops are no longer there but this 1975 photo of the building shows (arrowed) the same door, partially hidden by the stack of wood; it was set in the larger door that led into Stall 1 of the building. By then the shops had been made redundant by the advent of diesels and the building was being used by a lumber company. It was demolished in the mid 1980s.
Then ... He sees Glaucus busily chiseling the ice block into shape. The windows behind him at the back were those of the Machine Shop which ran the length of the building at the rear. (The Machine and Erecting Shops combined as one huge open space).
This 1983 photo of the back wall was taken at the opposite end of the building but you can see that the window details match the windows above.
Maude, naked, looks out cheerily from behind the ice block. She coquettishly confides to Harold later that she posed because ... "poor Glaucus occasionally needs his memory refreshed as to the contours of the female form".