There are 3 Northwestern PORTERFIELD 35-70 aircraft on the U.S. registry that TailWiki has a page for. Every one is built from the public FAA record — year, serial, engine, home base, and registration history — and owners and pilots add photos, trips, and stories on top. The ones listed here were built between 1935 and 1950.
N15457
1950 Northwestern PORTERFIELD 35-70
Gilroy, CA
N15444
1935 Northwestern PORTERFIELD 35-70
Krum, TX
N14475
Northwestern PORTERFIELD 35-70
Lockport, NY