The final solution - what I came up with regarding auxiliary propulsion (pic heavy)
Well, here it is - this is the solution for the problems that may be encountered cruising in tight quarters (fairways/locks/canals whatever), without any kind of permanently installed motor. It's an outboard motor bracket bracket...
The biggest problem I had was not with the idea of having a small outboard for times when it's needed, but rather with the notion of a hideous eyesore permanent motor bracket mounted on such a beautiful overhang.
So.. I designed this nifty little stainless steel device here:
I made sure the fit was precise, and the motor bracket (when dropped into the motor bracket bracket) is threaded and bolted thru, in addition to the zipper welds. You'll see what I mean when you look at the pics below..
I'll mount it over a heavy piece of black rubber (pictured below) and bed with butyl, and of course use a huge backing plate (again, pictured below).
Neat idea, hard to predict how usage over time will hold up. Could be a lot of weight and strain on those welds. I'm imagining that physically installing the outboard in the mount will be an exercise to some degree, ie retrieving it, leaning over the transom, tightening fasteners, etc.
Gasoline in a lazerete is a no no.
Giving up a lazerete to accommodate the increased space gained by removing the main engine is confusing.
Nice work, assuming the welds are sound. it would be interesting to see how long it takes to get the motor out and mounted, started and getting underway when a big barge or other commercial vessel is about to run you down. In your pictures it looked like your boat was about 30 feet. 3 to 4 HP may push it in calm waters with minimal current. If you have any chop where you are going you will need the longest shaft you can get or you will be "spinning your wheels". I guess it all depends on how often you will have to use it as to whether you leave it on permanently or mount it each time you need it. 3 to 4 HP seems kind of whimpy but it is a whole lot better than nothing. Curious about your battery charging capabilities?