LAPL/GoogleSV
The Mosher House got me interested in Old Monrovia... I hadn't realized that Upton Sinclair (whose book
The Jungle is a sure cure for nostalgia) lived in the pretty old burg, in a house similar to the Moshers' and just up the street at 464 N. Myrtle Ave. Its architect is documented as Frederick Wallis-- it seems likely that given the similarities and proximity of the two houses, he might have designed both.
Los Angeles Times 9-16-1923
Sinclair bought the house in 1943 and lived in it for about 25 years.