Windsor Hills was developed in the mid-to-late 1930s, about the time the stone became available. Oddly enough, Windsor Hills and City Terrace are both unincorporated areas. Maybe the city didn't want the county's old rocks or the county just decided it was easier to dump them where they didn't have to ask permission.
I don't see any carved bits of sandstone in the Ladera Park parking lot so it would be hard to prove where it came from except, of course, it's 240-million-year-old Moenkopi from Flagstaff. The Arizona Sandstone Company quarry sent 500 boxcars of it to Los Angeles in 1889 for the Courthouse. A big order. There were other orders from Los Angeles and Pasadena too. The Durand residence in Pasadena used stone from the Flagstaff quarry, for example.
Arizona red lost favor when it was noticed it deteriorated in other climates, which probably explains the fragility of our Courthouse.
The Brown Palace (1892) in Denver, which utilizes Colorado red granite as well as Arizona red sandstone, seems to be doing OK with a lot of maintenance, but the
Whittier Mansion (1896) in San Fransico had to be sealed and painted.
LA County Courthouse in the raw. Arizona Sandstone Company quarry, Flagstaff ca 1888:
geocaching
ca 1887
azdailysun
Flagstaff's own County Courthouse (1894) is doing fine:
pixelfugue
A new fire station has been built in the disused quarry site, if anyone has a mind to make a pilgrimage it's at
1701 Ponderosa Parkway, Flagstaff AZ 86001:

gsv
more info:
A History in Stone Uncovered
Arizona Red, A Once-Popular Building Stone
Buildings Built of Arizona Red Sandstone
HistoricAZ66: Flagstaff Quarry
Stories in Stone
Moenkopi Formation