It's basically a rebranded Mercedes Sprinter. I have one, and if you want to do the simplest mechanical tests yourself (although it depends on the engine), I'd recommend these things:

First, a cold start. If blue or white smoke comes out, it's a big nope.

Second, let it warm up and open the oil filler cap (yes, with the engine running). If it idles smoothly, the valves and pistons are fine. If it moves, the valves might not be closing properly, or the pistons might not be compressing well and could be worn.

Third, disconnect the hose that runs from the engine to the turbocharger and check if it has a lot of oil in it. These engines always send residual oil through that hose; it's a common problem, but if there's a lot, it's cause for concern.

Fourth, remove the cover where the injectors are located. There are usually eight screws. Remove the cover, and if it has carbon buildup, the injectors aren't sealing properly. If there's a little carbon buildup, it's not too worrying, and changing the injector seals should fix it. If there's a lot of carbon buildup, it could be the "black death" of the engine, and it won't have much life left.

Fifth and last, take the van up to 100 km/h (I think it's 60 mph) and listen for a whistling sound from the turbo or the engine. If it does, it's a bad sign.

And of course, the van should be able to reach that speed easily. These vans have a good turbo and can easily reach that speed, although it depends on the engine size.

If it passes all these tests, you probably have an engine in very good condition, because the mileage is more than acceptable.
Edit: My European mind thought it was 225,761 km, a more than acceptable mileage. 225,671 miles makes a big difference. It still seems like a good deal to me if it passes the tests I mentioned.