nearly all the merc motors from 7hp on up have mounting provisions for starter. some may or may not have the ring gear on the flywheel. some may or may not have a charging stator.
for the electric start conversion kit, there would be a solenoid, a small wiring harness, the starter button, etc along with the starter and the cables that gets added as the kit. some kits include the charging stator
for a motor that is nearly 44 years old, most of those parts new have the part number "NLA" for No Longer Available" and if you do find them, the parts will cost nearly as much as you paid for the motor. as Racerone pointed out, you will have to find a donor
usually its easiest and cheapest to sell what you got and get what you want.
