Sounds like a great opportunity! Be a good motor for the 19-6.
Before committing, do a compression test if feasible. Good pressure readings should be within 10%. Dribble a little oil out of the lower unit lower drain plug. If no water, all's well... buy it. While you're checking the oil, if the motor is still sitting where it's been stored, glance at the floor under the prop to see if there is an oily spot there. If there is, the gear case should be pressure-tested... a good precaution for any "unknown" motor.
Plan on rebuilding the carbs after you get it home. Although the motor is low hours, the gas in the carbs. isn't. Rebuilding's an easy job. Use O.E.M. parts & pick up the manufacturer's service manual for the how-to. If the plugs look clean, they're good.
There may be a few other minor things which might crop-up but basicially you should have a solid motor.
Please post some pictures and let the group know how you made out.
OOPS! almost forgot... definitely replace the water pump impeller. The rubber will have cracked or taken a "set" from sitting idle.