When I read of all of these modifications to the boat and motor they make me nervous. Here is why...
Unless there is something spectacular and unique about the Hughes model that was extended, then I think that the reason it was extended was because the owner wanted a bigger boat but could not afford to buy one. Therefore, he/she reasoned it would be cheaper to extend the current vesel.
Doing something like extending a boat by three feet is major structural work. It's a project that needs a lot of time and space, not to mention money. Any bonds between old and new fibreglass/epoxy are going to be suspect. The strength of a secondary bond rarely approaches the strength of primary ones. If the individual who extended the boat had done it properly, it would have cost many thousands of dollars, and would have been much more expensive an exercise than buying a longer boat to begin with.
Even when they are properly done, changes of that type rarely result in a craft that is balanced. The center of gravity is no longer where the sail plan's center of effort needs it to be. The result is a boat that will not sail well, and may even be unsafe.
Ditto for the motor. There is a lot of bad feeling out there for saildrives - some of it deserved and some not so deserved. What can be safely assumed though, is that the likelihood of an engine being a problem increase with each non-standard modification made to it. I believe that the Hughes 26's were sold with OMC Saildrives and that the OMC (Evinrude) is the brand that hs generated the most negative emotion. You first clue is that it has four hours on it. I am sure the vendor is hoping that it runs for another four or so until he an offload the craft.
If you are being seduced by a low, low price for a 28 foot boat - shake your head. This is not a 28 foot boat. This is a disabled 26 footer - someone's make work project.
If you want a good deal on a 28 foot boat, look in Michigan. It is a simple matter to get the boat up to Ontario, and you will get far, far more for your money there right now than you will anywhere in Canada.
Don't mean to burst your bubble but the vendor is not selling a "Hughes 28". They are trying to salvage some dollars from an expensive mistake.
Good Luck !