Hi Ken,
In response:
I replaced my 6hp engine a few years back and the Tohatsu dealer, following my query and consultation with whatever manuals, assured me that a long shaft was the correct outboard.
I have a blanking-plate, something slightly bigger than the hole which attaches/clips in, and covers the ‘hole in the bottom of the boat’; but I rarely use it. Earlier this year when on a pontoon with waves lashing the stern it was useful stopping water splashing up, but apart from that, I am not sure the point of it - you cannot/never been able to use it when the engine is on the transom/ply mounting board.
At the end of each sailing session, I lift my outboard right out of the water and it sits/rests on a homemade contraption. Not very hi-tech but functional. A picture was posted by the webmaster about 5 months ago under 'Lifting engine and keel position when on the mooring' - it is a straightforward lift and although I am of a ‘more mature persuasion’, not too difficult for me!
Hope this helps
Regards