Rebuilt an older (1995) LP1 at the beginning of the year, the heat exchanger looked very similar, if not identical. The old style are soldered on, the new style has removable end caps. If you have a radiator shop in your area they can check and service
it. Or if you have a propane
torch with a Mapp gas cylinder you can probably get it off. You could also pressure test it yourself by plugging the inlet pipe, putting a hose on the outlet pipe, submerging the whole exchanger in a tube of water
and blowing (10 psi or so) air into the hose. Any leaks
will blow bubbles.
Don't know where you're located, but there's a Kubota ZB600 engine on San Antonio craiglist now for 100.00. The ZB600 is the base engine for the LP2. Not marine
but it looks like you might need an intake manifold.
Also, since you're in there and they're cheap
, why not replace the rod bearings too? Seems a false economy not to...