motor mounting location

Recently purchased a 1986 14-1/2' Sylvan Backtroller (aluminum) and am in the process of replacing the transom. I just discovered that the 40 HP motor was mounted about 1" off center to the port side. Is it possible this was done intentionally for some reason or more likely done by accident? The area where the motor is mounted looks like swiss cheese and none of the holes are perpendicular to the transom so my guess is they were not drilled at the factory and I should drill the motor mounting hole on the centerline of the new transom. Also I intend to cover the "swiss cheese" area with an appropriately sized piece of aluminum riveted in place and sealed with silicone around the many holes and perimeter. I would appreciate any help

 

I sure don't think that would make sense to mount the motor off center. I would remount it in the center, If the transom is structurally sound then putting in replacement aluminum should work. You might want to look at a product called marine tex instead of silicone. It seals and gets real hard.