Thanks for the replies guys, I will try to put some pictures up. The transit had some scoring on the thrust sides but I'm pretty sure this happened after the crack as the gudgeon pin pushed the two halves apart. I did do a service on it afterwards & used injector cleaner. It's just been to Poland & back with no problems. I haven't got the ducato one out yet (should be by monday)but can see the crack with a bore scope down the injector hole. I've checked with both customers & they say they've been using normal diesel.

Just to add, local ford dealer told me they don't sell pistons separately-only a short engine! Got an aftermarket one (the same make as the one I took out)