Similar to Mercury Model KD4S (S indicates a recoil
starter) You can research ebay or go to aomci.org
place a free ad "best offer" and see if anything
happens.
Condition,Location and Supply/Demand set market value
and therefore price. Need for impeller or coils
significantly affect value. It is not unusual for outboard of this vintage to need complete overhaul.
Most purchasers would factor cost of likely repairs
into offer unless they have opportunity to look
motor over in person. Fun to tinker with and use
,but, no great value...unrestored old outboards
change hands at club meets for $25 to $50...a fully
and expertly restored old outboard will command more ,but, usually about the value
of old motor plus new parts...labor and paint
usually not reflected in selling price...