Going from what I've read and experienced over the past 18 months of ownership, the engines are bullet proof. The only things that can be checked is whether the spark plugs come out, this is the only weak point. Spark plugs that are seized and then removed means damaged threads, which as there are not many threads, means that they can be forced out by the engine. Other possible pitfalls, air con pump, water pipe etc are all external to the engine and can be replaced if you are unlucky enough to have a problem.

The engines may be rare in the UK but they are two-a-penny in the US.

Good luck!

Ian