I found on ebay an item related to the Los Angeles Eastside Airport:
1) A copy of
The Pilot, March, 1930 publication, which lists the address as 800 East Whittier Blvd. The would place the airport on the SW corner of what is now Whittier and Paramount blvds.
https://www.ebay.com/itm/195707962156
I also found an flight map showing the airport in Montebello as being in between the Rio Hondo and the San Gabriel River.
The map is credited as being from August 1933 LA Sectional Aeronautical Chart, and was found on the webpage created by Paul Freeman: "Abandoned & Little-Known Airfields: California: East Los Angeles Area":
http://www.airfields-freeman.com/ca/...E.htm#rosemead
Map:
http://www.airfields-freeman.com/ca/..._m5a5c78f6.jpg
The airport site is now a shopping mall, but previously it was the Paramount Drive-In Theater, a venue I was fully acquainted with in days past.