Yeah, I was wary when he told me about the engine but the Mazda WL-series engine is the same block as the WL-T (which is the standard Bongo diesel). On the test drive, I was able to do 60mph at 2200rpm which seemed standard enough. It took it's time getting there .
Funnily enough, the intercooler has been left in place because I was able to take a look and he showed me the air intake pipe, where the turbo would have been. Probably does not harm to leave the intercooler in place, it can't be that big, but it does seem strange.