Engine laziness
 

So, let's say just for an example, that I am a lazy bastard and leave an engine in my car unsealed for around 9 months, during which time amongst other thing it spends a month on a boat crossing the Atlantic...is it fubar'd?

Or just in need of a rebuild?

Or might it even just run ok?

And no...I did not use after run oil!

You need to get it apart and look at it for signs of corrosion... Moisture will have been your biggest enemy :(

i think you will find it will be all rusty inside as you havent used after run oil.

if it has a coated crank and gudgeon pin it will probably just need some bearings and be good to go, if not the crank and pin may have become pretty corroded making it unviable as a rebuild, only way to be sure though is to open it up and have a good butchers.

strip it, clean the crank and fit new bearings and plug and youll be ok
did you leave fuel in tank too? what fuel had you used?