Both my 1963 Cessna 150 with Continental O-200 and my 1946 Bellanca Cruisair with Franklin O-335 had impulse couplings on both mags. Hand propping was quite doable. The mags on the Franklin were timed to 28 BTDC, with the impulse couplings delaying the spark to just ATDC. A cylinder firing with more than maybe 5 degrees advance is sure to kick back.
Automatic spark advance on cars was rare before about 1930, which meant having a spark advance control lever on the steering column. Forget to retard the spark for starting, and you get a broken arm if cranking with the wrong hand. In fact, there is a certain break that was well known to doctors of the era. It was called a Ford fracture, or some such, as the self starter only became an option on the Model T in 1919, some years after most other cars had them.
GB