Has VRO oil consumption been tested / checked?----Lower unit gear oil checked / changed?----The gearcases on some of these are not robust in my opinion.----And have compression values been posted ?
In the early / mid 80's the motor rating was changed from power at the crankshaft to power at the prop.---So yes , an older motor had a higher number on the decals.
The " lean sneeze " is much mis-understood.----Adjust low speed mixture screws to get rid of it.----Most motors will sneeze a few times when cold.----Should disappear after 15/ 20 seconds after cold start.
On this motor the " safety switch " prevents cranking if throttle is advanced too far.---Just under the magplate.-----ONE white wire only to it.-----Contact INSIDE this switch can be dirty.
There is a safety switch under the magneto plate.----Prevents cranking if throttle is open too far.----Just ONE white wire on this switch !------The loose wires pictured might belong on the " cut out switch " for 1 cylinder.----It stops spark on one cylinder should there be a high...
In my opinion 1957 motors need a total evaluation of condition.----Tear down / inspection / replacement of consumable parts.----Unless they have warranty / proof that it was done recently.