There is an excellent book about Santa Fe depots on the Los Angeles Division written
by lee Gustafson and Phil Serpico. It is published by OMBI PUBLICATIONS, Palmdale,CA
93590-0566

The authors state that there was originally a carbody depot at San Onofre and in 1928 the depot from DREW (built in 1888) was moved to this location and the carbody converted to other use. It was retired and removed in 1953. On page 196 there is an excellent photo of this 1888 structure with the name San Anofre on both the end and trackside.