Can't locate the top drain plug on the lower unit.Bottom one was easy.
Any help would be appreciated.

Vent is on right side of "Drive Shaft Housing-lower" on Mercury Mark 5 and KF5 so likely same
on your Wizard Super Five.
(right as viewed from rear) looks like a screw head
as it is only a vent...lube is added and drained
at the fitting you have located)
Louis

Thanks, I found it. It was covered with "crud". lol

Sincerely,
Nile