Will you have shorepower where you keep it? With it, you can make an engine start much easier through several different methods. The easiest is to aim a heat gun at the air intake for a little while. You could also put an oil pan heater on which helps with cranking speed and does heat the block a little. Another option would be to heat the compartment. With all of these you want to be careful about making it safe. Unfortunately, you can't really hook up a conventional coolant block heater on a raw water cooled engine.
Yep, there would be shorepower and those are some options to consider. Thanks.
I think the bigger issue is simply whether or not the engine as a whole is worth the risk given that it is raw water and has spent its life in saltwater. Especially since on a boat of this vintage, an engine repair/replacement is such a large proportion of the overall cost/financial worth of the boat. I suppose the best that can be done is to have a diesel survey and take a chance if I want to go with this boat.
As mentioned, in a perfect world I would prefer a different engine and it has given me enough pause to consider buying other boats with newer engines. Then I have to keep reminding myself I'm not simply looking to buy an engine.