I've got some experience with older boats...
I'd evaluate what you have on hand first. How good is the hull? The older hulls all used wood as the core for the transom and for the stringers. Wood, as we unfortunately know, does not last for ever.
Perhaps the best thing might be to get a marine surveyor or very experienced hull guy to take a look at the boat. Even if there are problems, it might be worth fixing it rather than buying new. Especially since the 19 mako is known as a good hull.
Then, if you're convinced that the hull is sound, look for a left over year or two old engine (that's new). You may find something on the web. I've had good luck with Atlantic Outboard
I've got to think that you're better off repowering and retrailering your mako.
Let's do some rough math:
New Engine - Call it $6,500
New Trailer - Call it $3k
(or replace and repack your bearings, rewire, and buy a good spare tire, $500)
Either 7k or 9.5k vs. a new maritime which will run a whole lot more...
Of course, trailering back and fourth could be a little tough on your vehicle...